Update index.html

Author: mulle-nat

index.html

@@ -140,7 +140,7 @@ <h2>+[mulle-objc support]</h2>
       Support the project by <a href="https://github.com/mulle-objc/mulle-objc.github.io/issues/1">becoming a public member</a> of <tt>mulle-objc</tt> and 
       to get a nice logo for your github profile: 
       <p>
-      <img src="https://avatars0.githubusercontent.com/u/23309093?s=80&v=4">
+      <img src="pix/mulle-objc-logo-opaque.svg" width="48" height="48"">
       <p>
 
       Thanks to our Sponsor(s) for supporting the project.