Fix condition

synapse/handlers/register.py

@@ -293,7 +293,7 @@ class RegistrationHandler(BaseHandler):
 
         # Prevent the new user from showing up in the user directory if the server
         # mandates it.
-        if self._show_in_user_directory:
+        if not self._show_in_user_directory:
             yield self.store.add_account_data_for_user(
                 user_id, "im.vector.hide_profile", {'hide_profile': True},
             )