Merge branch 'gitaly-write-repo-config-prep' into 'master'

Move rugged-call from Project#write_repository_config to Git::Repository#write_config

See merge request gitlab-org/gitlab-ce!16572

app/models/project.rb

@@ -1438,7 +1438,7 @@ class Project < ActiveRecord::Base
     # We'd need to keep track of project full path otherwise directory tree
     # created with hashed storage enabled cannot be usefully imported using
     # the import rake task.
-    repository.rugged.config['gitlab.fullpath'] = gl_full_path
+    repository.raw_repository.write_config(full_path: gl_full_path)
   rescue Gitlab::Git::Repository::NoRepository => e
     Rails.logger.error("Error writing to .git/config for project #{full_path} (#{id}): #{e.message}.")
     nil

lib/gitlab/git/repository.rb

@@ -1317,6 +1317,10 @@ module Gitlab
       end
       # rubocop:enable Metrics/ParameterLists
 
+      def write_config(full_path:)
+        rugged.config['gitlab.fullpath'] = full_path if full_path.present?
+      end
+
       def gitaly_repository
         Gitlab::GitalyClient::Util.repository(@storage, @relative_path, @gl_repository)
       end