FIX: Don't error on rooms the user has left already

src/RoomInvite.js

@@ -191,14 +191,11 @@ function _showAnyInviteErrors(addrs, room) {
 function _getDirectMessageRooms(addr) {
     const dmRoomMap = new DMRoomMap(MatrixClientPeg.get());
     const dmRooms = dmRoomMap.getDMRoomsForUserId(addr);
-    const rooms = [];
-    dmRooms.forEach((dmRoom) => {
+    const rooms = dmRooms.filter((dmRoom) => {
         const room = MatrixClientPeg.get().getRoom(dmRoom);
         if (room) {
             const me = room.getMember(MatrixClientPeg.get().credentials.userId);
-            if (me.membership == 'join') {
-                rooms.push(room);
-            }
+            return me && me.membership == 'join';
         }
     });
     return rooms;