Check the deleted room exists before refreshing

src/matrix/Sync3.ts

@@ -368,7 +368,9 @@ export class Sync3 {
             // However, I failed to reproduce this so ¯\_(ツ)_/¯¯
             deletedRoomIDs.concat(addedRoomIDs).forEach((roomId) => {
                 let room = this.session.rooms.get(roomId);
+                if (room) {
                     room.forceRefresh();
+                }
             })
 
             // END sync v3 specific