Weird network crash fix in MSIX deployment.

Author: blakepell

src/Avalon.Client/HashCommands/Beep.cs

@@ -65,11 +65,11 @@ public override void Execute()
                                                return;
                                            }
 
-                                           App.Beep.Play();
+                                           App.Beep?.Play();
 
                                            return;
                                        default:
-                                           SystemSounds.Beep.Play();
+                                           SystemSounds.Beep?.Play();
                                            return;
                                    }
                                });

src/Avalon.Client/MainWindow.Network.cs

@@ -139,7 +139,7 @@ public void HandleLineReceived(object sender, string e)
             // One beep per line max, everything else is ignored.
             if (App.Settings.ProfileSettings.AnsiBeep && e.Contains('\a'))
             {
-                App.Beep.Play();
+                App.Beep?.Play();
             }
 
             try