Rails deprecation warning on except!

[atz]

DEPRECATION WARNING: 
Method except! is deprecated and will be removed in Rails 5.1, 
as `ActionController::Parameters` no longer inherits from hash. 
Using this deprecated behavior exposes potential security problems. 
If you continue to use this method you may be creating a security vulnerability 
in your app that can be exploited. Instead, consider using one of these documented 
methods which are not deprecated: 
http://api.rubyonrails.org/v5.0.0.1/classes/ActionController/Parameters.html 
(called from advanced_search_context at .../app/helpers/advanced_helper.rb:37)

Link http://api.rubyonrails.org/v5.0.0.1/classes/ActionController/Parameters.html

Warning appears 14 times during rake ci.