Fix coloring of build result links in the new webui

The 'failed' link for the build results should be red, but it was blue.

This broke when moving the defined result colors to a CSS file (f589a07).

src/api/app/assets/stylesheets/webui2/build-results.scss

@@ -34,7 +34,7 @@
   color: $dark;
 }
 
-.build-state-unresolvable, .build-state-broken {
+.build-state-unresolvable, .build-state-broken, .build-state-failed {
   color: $red;
 }