title: How to remove a protected commit using BFG
body: <p>When cleaning the repo with BFG (<a href="https://rtyley.github.io/bfg-repo-cleaner/" rel="noreferrer">https://rtyley.github.io/bfg-repo-cleaner/</a>) ,encountered the following : </p>
  
  <pre><code>Protected commits
  -----------------
  
  These are your protected commits, and so their contents will NOT be altered:
  
   * commit ******* (protected by 'HEAD')
  </code></pre>