Fix login check in commands

mautrix_signal/matrix.py

@@ -68,10 +68,6 @@ class MatrixHandler(BaseMatrixHandler):
 
         await portal.handle_matrix_leave(user)
 
-    @staticmethod
-    async def allow_bridging_message(user: 'u.User', portal: 'po.Portal') -> bool:
-        return user.is_whitelisted and bool(user.username)
-
     # @staticmethod
     # async def handle_redaction(room_id: RoomID, user_id: UserID, event_id: EventID,
     #                            redaction_event_id: EventID) -> None:

mautrix_signal/user.py

@@ -65,6 +65,9 @@ class User(DBUser, BaseUser):
             return None
         return Address(uuid=self.uuid, number=self.username)
 
+    async def is_logged_in(self) -> bool:
+        return bool(self.username)
+
     async def on_signin(self, account: Account) -> None:
         self.username = account.username
         self.uuid = account.uuid