integrations: reduce logging on override integration from warn to debug.

rhodecode/integrations/registry.py

@@ -30,7 +30,7 b' class IntegrationTypeRegistry(collection'
     def register_integration_type(self, IntegrationType):
         key = IntegrationType.key
         if key in self:
-            log.warning(
+            log.debug(
                 'Overriding existing integration type %s (%s) with %s' % (
                     self[key], key, IntegrationType))