clean up config error logic and imports

1 files changed, 4 insertions, 5 deletions

diff --git a/synapse/config/registration.py b/synapse/config/registration.py
index 43ff20a637..4b9bf6f2d1 100644
--- a/synapse/config/registration.py
+++ b/synapse/config/registration.py
@@ -15,11 +15,10 @@
 
 from distutils.util import strtobool
 
-from synapse.config._base import ConfigError
 from synapse.types import RoomAlias
 from synapse.util.stringutils import random_string_with_symbols
 
-from ._base import Config
+from ._base import Config, ConfigError
 
 
 class RegistrationConfig(Config):
@@ -48,7 +47,7 @@ class RegistrationConfig(Config):
         self.auto_join_rooms = config.get("auto_join_rooms", [])
         for room_alias in self.auto_join_rooms:
             if not RoomAlias.is_valid(room_alias):
-                raise ConfigError('Invalid auto_join_rooms entry %s' % room_alias)
+                raise ConfigError('Invalid auto_join_rooms entry %s' % (room_alias,))
         self.autocreate_auto_join_rooms = config.get("autocreate_auto_join_rooms", True)
 
     def default_config(self, **kwargs):
@@ -106,10 +105,10 @@ class RegistrationConfig(Config):
         #    - "#example:example.com"
 
         # Where auto_join_rooms are specified, setting this flag ensures that the
-        # the rooms exists by creating them when the first user on the
+        # the rooms exist by creating them when the first user on the
         # homeserver registers.
         # Setting to false means that if the rooms are not manually created,
-        # users cannot be auto joined since they do not exist.
+        # users cannot be auto-joined since they do not exist.
         autocreate_auto_join_rooms: true
         """ % locals()