Fix Connections deprecation warning on Qt 5.15

Adopt the correct behavior to get rid of
"QML Connections: Implicitly defined onFoo properties in Connections
 are deprecated. Use this syntax instead:
 function onFoo(<arguments>) { ... }"

src/gui/Pages/Chat/RoomPane/RoomPane.qml

@@ -71,8 +71,9 @@ MultiviewPane {
     Connections {
         target: swipeView
 
-        onCurrentItemChanged:
+        function onCurrentItemChanged() {
             swipeView.currentItem.keybindFocusItem.forceActiveFocus()
+        }
     }
 
     MemberView {}