Unable to change source branch in GitHub Pages : <p>I have created a simple web site for GitHub Pages. The source of the site is in the "master" branch and the generated web site (what I want to see published) is under the "gh-pages" branch.</p>

<p><a href="https://i.stack.imgur.com/NQQpR.png" rel="noreferrer"><img src="https://i.stack.imgur.com/NQQpR.png" alt="Branches"></a></p>

<p>I was expecting to be able to change the source of the site in the settings. However, the setting is grayed out? I cannot change it (see screenshot below). What am I doing wrong? How do I switch to the "gh-pages" branch?</p>

<p><a href="https://i.stack.imgur.com/rwWY9.png" rel="noreferrer"><img src="https://i.stack.imgur.com/rwWY9.png" alt="enter image description here"></a></p>
