Keep usernames link-colored in collapsed comments

It's a bit difficult to read with the username link being the same color
as the comment text, this looks a little better to me.

tildes/scss/_themes.scss

@@ -126,10 +126,6 @@
   %collapsed-theme {
     header {
       background-color: $background-color;
-
-      .link-user {
-        color: $text-color;
-      }
     }
   }