Fixed deprecated selector in form_collections_helper_test.rb with fro…

…m catch_invalid_selector. Sweet.

actionview/test/template/form_collections_helper_test.rb

@@ -218,7 +218,7 @@ def with_collection_check_boxes(*args, &block)
     collection = [Category.new(1, 'Category 1'), Category.new(2, 'Category 2')]
     with_collection_check_boxes :user, :category_ids, collection, :id, :name, {}, {name: "user[other_category_ids][]"}
 
-    assert_select "input[type=hidden][name='user[other_category_ids][]'][value=]", :count => 1
+    assert_select "input[type=hidden][name='user[other_category_ids][]'][value='']", :count => 1
   end
 
   test 'collection check boxes generates a hidden field with index if it was provided' do