Fix async not waited warning

Author: golf1052

Signal-Windows/Controls/Conversation.xaml.cs

@@ -216,7 +216,8 @@ public void Load(SignalConversation conversation)
              */
             if (conversationThreadIdChanged)
             {
-                LoadDraft();
+                // We don't need to wait for this
+                _ = LoadDraft();
             }
             UserInputBar.FocusTextBox();
             DisposeCurrentThread();