Change the link it is redirecting to - Fix ahref issue (mmistakes#4882)

ahref is warning about this since the link redirects to the new path

_includes/footer.html

@@ -18,4 +18,4 @@
   </ul>
 </div>
 
-<div class="page__footer-copyright">&copy; {{ site.time | date: '%Y' }} <a href="{{ site.copyright_url | default: site.url }}">{{ site.copyright | default: site.title }}</a>. {{ site.data.ui-text[site.locale].powered_by | default: "Powered by" }} <a href="https://jekyllrb.com" rel="nofollow">Jekyll</a> &amp; <a href="https://mademistakes.com/work/minimal-mistakes-jekyll-theme/" rel="nofollow">Minimal Mistakes</a>.</div>
+<div class="page__footer-copyright">&copy; {{ site.time | date: '%Y' }} <a href="{{ site.copyright_url | default: site.url }}">{{ site.copyright | default: site.title }}</a>. {{ site.data.ui-text[site.locale].powered_by | default: "Powered by" }} <a href="https://jekyllrb.com" rel="nofollow">Jekyll</a> &amp; <a href="https://mademistakes.com/work/jekyll-themes/minimal-mistakes/" rel="nofollow">Minimal Mistakes</a>.</div>