Fixed chat room listener when in GroupChatFragment (this fragment onResume is called before the onPause of the previous one...)

src/android/org/linphone/chat/ChatListFragment.java

@@ -141,7 +141,7 @@ public class ChatListFragment extends Fragment implements OnItemClickListener, C
 
 		refreshChatRoomsList();
 	}
-
+	
 	@Override
 	public void onPause() {
 		Core lc = LinphoneManager.getLcIfManagerNotDestroyedOrNull();

src/android/org/linphone/chat/ChatRoomsAdapter.java

@@ -110,9 +110,6 @@ public class ChatRoomsAdapter extends ListSelectionAdapter {
 	}
 
 	public void clear() {
-		for (ChatRoom room : mRooms) {
-			room.setListener(null);
-		}
 		mRooms.clear();
 	}