[fractal/fractal-next] room_list: Use get index instead of using nth

[Julian Sparber <jsparber src gnome org>]

commit 0142c21c2bd331b29a906493fa092b3fed5d9c73
Author: SeaDve <davecruz48 gmail com>
Date:   Thu Sep 16 20:32:11 2021 +0800

    room_list: Use get index instead of using nth
    
    It is a bit faster on larger collections since nth calls next on every item until
    it becomes None, while get_index is similar to a Vec's get method

 src/session/room_list.rs | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)
---
diff --git a/src/session/room_list.rs b/src/session/room_list.rs
index 41bfe1e1..5ba9c580 100644
--- a/src/session/room_list.rs
+++ b/src/session/room_list.rs
@@ -93,9 +93,8 @@ mod imp {
         fn item(&self, _list_model: &Self::Type, position: u32) -> Option<glib::Object> {
             self.list
                 .borrow()
-                .values()
-                .nth(position as usize)
-                .map(glib::object::Cast::upcast_ref::<glib::Object>)
+                .get_index(position as usize)
+                .map(|(_, v)| v.upcast_ref::<glib::Object>())
                 .cloned()
         }
     }