Fixing error message

Author: apetenchea

arangoasync/auth.py

@@ -103,7 +103,7 @@ def needs_refresh(self, leeway: int = 0) -> bool:
     def _validate(self) -> None:
         """Validate the token."""
         if type(self._token) is not str:
-            raise TypeError("Token must be str or bytes")
+            raise TypeError("Token must be str")
 
         jwt_payload = jwt.decode(
             self._token,