Listing all pull requests does not work for renamed forks


#1

For example https://api.github.com/repos/theia-ide/theia/pulls?head=theia-demo-plugins:master&per_page=1 should have returned on pull request.

I was able to work it around with including the new repo name into head ref, i.e. theia-demo-plugins/wiptheia:master. But i am not sure whether it is a proper work around.