title: GitHub can't rebase my feature branch: "This branch cannot be rebased due to conflicts"
body: <p>Even when my feature branch was branched out from the latest version of <code>master</code>, when I attempt to rebase my PR (from feature X to master), I end up seeing:</p>
  
  <p><strong>This branch cannot be rebased due to conflicts</strong>
  Rebasing the commits of this branch on top of the base branch cannot be performed automatically due to conflicts encountered while reapplying the individual commits from the head branch.</p>
  
  <p>I understand that this can be resolved by:</p>
  
  <pre><code>git checkout master
  git rebase feature/x
  (resolve conflicts)
  </code></pre>
  
  <p>However, direct pushing to <code>master</code> is locked and I need to go through a PR. What are the steps to successfully be able to rebase a <code>feature/x</code> branch to master through a pull request?</p>