[fractal] Added error log when failing to join room by ID

[Julian Sparber <jsparber src gnome org>]

commit 3e224af49e99fd299cb412622f6d7c5d4a2dac7d
Author: Wyatt Turner <wyatturner 45 gmail com>
Date:   Thu Apr 1 12:53:56 2021 -0700

    Added error log when failing to join room by ID

 fractal-gtk/src/appop/room.rs | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
---
diff --git a/fractal-gtk/src/appop/room.rs b/fractal-gtk/src/appop/room.rs
index 0ec69514..49ba6cc8 100644
--- a/fractal-gtk/src/appop/room.rs
+++ b/fractal-gtk/src/appop/room.rs
@@ -533,7 +533,8 @@ impl AppOp {
 
         let room_id = match try_room_id {
             Ok(room_id) => room_id,
-            Err(_) => {
+            Err(err) => {
+                error!("The room ID is malformed: {}", err);
                 let error = i18n("The room ID is malformed");
                 APPOP!(show_error, (error));
                 return;