Fix grammatical error in error message (#12483)

* Fix grammatical error in error message

* changelog

changelog.d/12483.misc

@@ -0,0 +1 @@
+Fix grammatical error in federation error response when the room version of a room is unknown.

synapse/storage/databases/main/state.py

@@ -130,7 +130,7 @@ class StateGroupWorkerStore(EventsWorkerStore, SQLBaseStore):
         )
 
         if room_version is None:
-            raise NotFoundError("Could not room_version for %s" % (room_id,))
+            raise NotFoundError("Could not find room_version for %s" % (room_id,))
 
         return room_version