#sort_link no longer removes params

This fixes an issue with sort_link removing non ransack params from the URL's it generates.

Consider a view that uses two sort/search mechanism: ransack and something else, which works in a similar way. This view uses params[:q] for ransack and params[:r] for the other thing. The controller uses both params to get its collection of records

    other_search(params[:r]).search(params[:q])

Currently sort_link will remove params[:r] thus resetting the other_search, so the two searches can't combine. This small change fixes that.