[fractal] chore: Switch to Rust 2021 edition

[Marge Bot <marge-bot src gnome org>]

commit 6203ba01b362095719bd7a7d36944672e86b9d0f
Author: Kévin Commaille <zecakeh tedomum fr>
Date:   Tue Oct 4 11:50:34 2022 +0200

    chore: Switch to Rust 2021 edition
    
    Part-of: <https://gitlab.gnome.org/GNOME/fractal/-/merge_requests/1176>

 Cargo.toml                                          | 2 +-
 src/contrib/qr_code.rs                              | 1 -
 src/login/idp_button.rs                             | 2 --
 src/session/content/explore/public_room_list.rs     | 2 --
 src/session/content/room_details/member_page/mod.rs | 2 --
 src/session/mod.rs                                  | 2 +-
 src/session/room/room_type.rs                       | 2 +-
 src/session/sidebar/category.rs                     | 2 +-
 src/session/sidebar/mod.rs                          | 5 +----
 src/session/sidebar/row.rs                          | 2 --
 src/utils.rs                                        | 2 +-
 11 files changed, 6 insertions(+), 18 deletions(-)
---
diff --git a/Cargo.toml b/Cargo.toml
index caaeeb3cc..703a88a42 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -2,7 +2,7 @@
 name = "fractal"
 version = "5.0.0-alpha1"
 authors = ["Julian Sparber <julian sparber net>"]
-edition = "2018"
+edition = "2021"
 rust-version = "1.60"
 
 [profile.release]
diff --git a/src/contrib/qr_code.rs b/src/contrib/qr_code.rs
index 782854639..46049a9fb 100644
--- a/src/contrib/qr_code.rs
+++ b/src/contrib/qr_code.rs
@@ -1,6 +1,5 @@
 // Taken from https://gitlab.gnome.org/msandova/trinket/-/blob/master/src/qr_code.rs
 // All credit goes to Maximiliano
-use std::convert::TryFrom;
 
 use gtk::{glib, prelude::*, subclass::prelude::*};
 
diff --git a/src/login/idp_button.rs b/src/login/idp_button.rs
index 54accf0f0..0d67cd2c6 100644
--- a/src/login/idp_button.rs
+++ b/src/login/idp_button.rs
@@ -1,5 +1,3 @@
-use std::convert::{TryFrom, TryInto};
-
 use gtk::{self, glib, glib::clone, prelude::*, subclass::prelude::*, CompositeTemplate};
 use matrix_sdk::ruma::api::client::session::get_login_types::v3::{
     IdentityProvider, IdentityProviderBrand,
diff --git a/src/session/content/explore/public_room_list.rs b/src/session/content/explore/public_room_list.rs
index 987c2fe10..8c72548df 100644
--- a/src/session/content/explore/public_room_list.rs
+++ b/src/session/content/explore/public_room_list.rs
@@ -1,5 +1,3 @@
-use std::convert::TryFrom;
-
 use gtk::{gio, glib, glib::clone, prelude::*, subclass::prelude::*};
 use log::error;
 use matrix_sdk::ruma::{
diff --git a/src/session/content/room_details/member_page/mod.rs 
b/src/session/content/room_details/member_page/mod.rs
index f0924a241..eff38045c 100644
--- a/src/session/content/room_details/member_page/mod.rs
+++ b/src/session/content/room_details/member_page/mod.rs
@@ -71,8 +71,6 @@ mod imp {
             });
 
             klass.install_action("members.subpage", Some("u"), move |widget, _, param| {
-                use std::convert::TryFrom;
-
                 let state = param
                     .and_then(|variant| variant.get::<u32>())
                     .and_then(|u| Membership::try_from(u).ok());
diff --git a/src/session/mod.rs b/src/session/mod.rs
index f59b08bbd..5f3020786 100644
--- a/src/session/mod.rs
+++ b/src/session/mod.rs
@@ -10,7 +10,7 @@ mod sidebar;
 mod user;
 pub mod verification;
 
-use std::{collections::HashSet, convert::TryFrom, fs, path::PathBuf, time::Duration};
+use std::{collections::HashSet, fs, path::PathBuf, time::Duration};
 
 use adw::subclass::prelude::BinImpl;
 use futures::StreamExt;
diff --git a/src/session/room/room_type.rs b/src/session/room/room_type.rs
index 1cbe46776..d8af6f4a7 100644
--- a/src/session/room/room_type.rs
+++ b/src/session/room/room_type.rs
@@ -1,4 +1,4 @@
-use std::{convert::TryFrom, fmt};
+use std::fmt;
 
 use gtk::glib;
 use num_enum::{IntoPrimitive, TryFromPrimitive};
diff --git a/src/session/sidebar/category.rs b/src/session/sidebar/category.rs
index 1ac4b0917..3955cf52d 100644
--- a/src/session/sidebar/category.rs
+++ b/src/session/sidebar/category.rs
@@ -7,7 +7,7 @@ use crate::session::{
 };
 
 mod imp {
-    use std::{cell::Cell, convert::TryFrom};
+    use std::cell::Cell;
 
     use once_cell::unsync::OnceCell;
 
diff --git a/src/session/sidebar/mod.rs b/src/session/sidebar/mod.rs
index a32f4cacb..36692ee7f 100644
--- a/src/session/sidebar/mod.rs
+++ b/src/session/sidebar/mod.rs
@@ -42,10 +42,7 @@ use crate::{
 };
 
 mod imp {
-    use std::{
-        cell::{Cell, RefCell},
-        convert::TryFrom,
-    };
+    use std::cell::{Cell, RefCell};
 
     use glib::{signal::SignalHandlerId, subclass::InitializingObject};
     use once_cell::{sync::Lazy, unsync::OnceCell};
diff --git a/src/session/sidebar/row.rs b/src/session/sidebar/row.rs
index 0c375ba27..aff2e0ad9 100644
--- a/src/session/sidebar/row.rs
+++ b/src/session/sidebar/row.rs
@@ -1,5 +1,3 @@
-use std::convert::TryFrom;
-
 use adw::{prelude::*, subclass::prelude::*};
 use gtk::{gdk, glib, glib::clone};
 
diff --git a/src/utils.rs b/src/utils.rs
index 942a9b566..8b33a623e 100644
--- a/src/utils.rs
+++ b/src/utils.rs
@@ -166,7 +166,7 @@ macro_rules! _add_toast {
     }};
 }
 
-use std::{convert::TryInto, path::PathBuf, str::FromStr};
+use std::{path::PathBuf, str::FromStr};
 
 use gettextrs::gettext;
 use gtk::{