Correct typo in README branch name
Correct typo in README branch name

MarkEWaite/git-plugin,jenkinsci/git-plugin,MarkEWaite/git-plugin,jenkinsci/git-plugin,martinda/git-plugin,jenkinsci/git-plugin,jenkinsci/git-plugin,MarkEWaite/git-plugin,martinda/git-plugin,MarkEWaite/git-plugin,martinda/git-plugin