Fix panic in API pulls when headbranch does not exist (#10676)
* Fix panic in API pulls when headbranch does not exist
* refix other reference to plumbing.ErrReferenceNotFound
Signed-off-by: Andrew Thornton <art27@cantab.net>
This module is merged from https://github.com/go-gitea/git which is a Go module to access Git through shell commands. Now it’s a part of gitea’s main repository for easier pull request.