Fix namespace selector on Projects#new page

If user does not own any group he does not see namespace selector when
visit new project page even if he has master membership in one of
groups. This commit fixes it.
Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

app/models/user.rb

@@ -372,7 +372,7 @@ class User < ActiveRecord::Base
   end
 
   def several_namespaces?
-    owned_groups.any?
+    owned_groups.any? || masters_groups.any?
   end
 
   def namespace_id