No need to rescue Rugged::ConfigError in RepositoryMirroring

Signed-off-by: Rémy Coutable <remy@rymai.me>

app/models/concerns/repository_mirroring.rb

@@ -17,9 +17,6 @@ module RepositoryMirroring
 
     raw_repository.rugged.config["remote.#{remote_name}.mirror"] = true
     raw_repository.rugged.config["remote.#{remote_name}.prune"] = true
-  rescue Rugged::ConfigError
-    # Ignore multivar errors when the config already exist
-    # TODO: refactor/fix this
   end
 
   def add_remote_fetch_config(remote_name, refspec)