Update sponsor button

source/_templates/sidebarlogo.html

@@ -2,7 +2,7 @@
 <p><iframe src="https://ghbtns.com/github-btn.html?user=mariatta&type=follow&count=false"
   allowtransparency="true" frameborder="0" scrolling="0" width="200" height="20"></iframe></p>
 
-<p><a href="https://github.com/users/Mariatta/sponsorship"><img src="https://img.shields.io/badge/sponsor-%E2%9D%A4%EF%B8%8F-blue.svg"></a></p>
+<p><a href="https://github.com/users/Mariatta/sponsorship"><img src="https://mariatta.ca/github-buttons/github-btn.html?user=mariatta&type=sponsor"></a></p>
 
 <p><a href="https://twitter.com/mariatta" class="twitter-follow-button" data-show-count="false">Follow @mariatta</a> <script>!function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0],p=/^http:/.test(d.location)?'http':'https';if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src=p+'://platform.twitter.com/widgets.js';fjs.parentNode.insertBefore(js,fjs);}}(document, 'script', 'twitter-wjs');</script></p>