Don't pass `:class` option and a query parameter in generated url

lib/ransack/helpers/form_helper.rb

@@ -130,7 +130,7 @@ module Ransack
 
         def url_options
           @params.merge(
-            @options.merge(
+            @options.except(:class).merge(
               @search.context.search_key => search_and_sort_params))
         end
 

spec/ransack/helpers/form_helper_spec.rb

@@ -735,6 +735,7 @@ module Ransack
           )
         }
         it { should match /class="sort_link desc people"/ }
+        it { should_not match /people\?class=people/ }
       end
 
       describe '#sort_link with class option workaround' do
@@ -748,6 +749,7 @@ module Ransack
           )
         }
         it { should match /class="sort_link desc people"/ }
+        it { should_not match /people\?class=people/ }
       end
 
       describe '#search_form_for with default format' do