Fix typos in Client.fetch() docstring (#432)

Author: larsw

terminusdb_client/client/Client.py

@@ -1717,7 +1717,7 @@ def pull(
     def fetch(self, remote_id: str,
               remote_auth: Optional[dict] = None,
               ) -> dict:
-        """Fatch the brach from a remote
+        """Fetch the branch from a remote repo
 
         Parameters
         ----------