Allow git access

This in run in bulk migration update loop,
so access can't be avoided.

ee/lib/gitlab/background_migration/migrate_approver_to_approval_rules.rb

@@ -66,9 +66,11 @@ module Gitlab
         end
 
         def sync_code_owners_with_approvers
+          Gitlab::GitalyClient.allow_n_plus_1_calls do
             ::MergeRequest.find(id).sync_code_owners_with_approvers
           end
         end
+      end
 
       class Project < ActiveRecord::Base
         self.table_name = 'projects'