github doesn't use .io urls

Library/Homebrew/cmd/audit.rb

@@ -204,8 +204,10 @@ class FormulaAuditor
       problem "Google Code homepage should end with a slash (url is #{f.homepage})."
     end
 
-    if f.homepage =~ %r[^http://.*\.github\.com/]
-      problem "GitHub pages should use the github.io domain (url is #{f.homepage})"
+    if f.homepage =~ %r[^http://(.*)\.github\.com/]
+      if $1 != 'github'
+        problem "GitHub pages should use the github.io domain (url is #{f.homepage})"
+      end
     end
 
     urls = @specs.map(&:url)