title: Github, dont do default pull request to master
body: <p>Everytime I make a pull-request from my fork to the original repo, Github first opens and compares my branch to the remote master branch. But thats never my target, and because there are so many files different, Github needs some time to complete the compare. Thats very annoying.</p>
  
  <p>How can I mae Github, not to compare to the remote master-branch but to default to another one when I click pull request?</p>