Partially revert recent RoomMedia change to make it work again

This reverts part of f288367653 which
touches this file. I'm not entirely sure why it was changed, it looks
like a piece of refactoring that isn't complete yet, but MessageDelegate
still depends on a required room property.

src/roominfo/RoomMedia.qml

@@ -50,18 +50,18 @@ QQC2.ScrollView {
             DelegateChoice {
                 roleValue: Timeline.MediaMessageFilterModel.Image
                 delegate: Timeline.MessageDelegate {
-                    Timeline.Message.room: root.room
                     alwaysFillWidth: true
                     cardBackground: false
+                    room: root.room
                 }
             }
 
             DelegateChoice {
                 roleValue: Timeline.MediaMessageFilterModel.Video
                 delegate: Timeline.MessageDelegate {
-                    Timeline.Message.room: root.room
                     alwaysFillWidth: true
                     cardBackground: false
+                    room: root.room
                 }
             }
         }