Fix Daniel's email in config file for website footer

Author: nuest

_config.yml

@@ -48,7 +48,7 @@ footer_icons:
     url: mailto:[email protected]
     icon: icon-email.svg
   - username: D. Nüst
-    url: mailto:daniel.nuest@uni-muenster.de
+    url: mailto:daniel.nuest@tu-dresden.de
     icon: icon-email.svg
 
 header_pages: