fetch and prune cache also

Author: tmu-sprd

lib/r10k/git/stateful_repository.rb

@@ -63,6 +63,7 @@ def sync(ref, force=true, exclude_spec=true)
       if force
         logger.warn(_("Overwriting local modifications to %{repo_path}") % {repo_path: @repo.path})
         logger.debug(_("Updating %{repo_path} to %{ref}") % {repo_path: @repo.path, ref: ref })
+        @repo.fetch
         @repo.prune
         @repo.checkout(sha, {:force => force})
       else