Fix #4906 Only apply filters if it has a value other than empty (#4913)
Fix #4906 Only apply filters if it has a value other than empty (#4913)

* Fix #4906 a more proper way (without breaking filters)

greg0ire/SonataAdminBundle,dmarkowicz/SonataAdminBundle,ossinkine/SonataAdminBundle,Armstrong1992/SonataAdminBundle,ossinkine/SonataAdminBundle,OskarStark/SonataAdminBundle,ARTACK/SonataAdminBundle,jordisala1991/SonataAdminBundle,ARTACK/SonataAdminBundle,osavchenko/SonataAdminBundle,mweimerskirch/SonataAdminBundle,peter-gribanov/SonataAdminBundle,osavchenko/SonataAdminBundle,peter-gribanov/SonataAdminBundle,sonata-project/SonataAdminBundle,osavchenko/SonataAdminBundle,dmarkowicz/SonataAdminBundle,mweimerskirch/SonataAdminBundle,OskarStark/SonataAdminBundle,ARTACK/SonataAdminBundle,OskarStark/SonataAdminBundle,dmarkowicz/SonataAdminBundle,sonata-project/SonataAdminBundle,osavchenko/SonataAdminBundle,dmarkowicz/SonataAdminBundle,ossinkine/SonataAdminBundle,ARTACK/SonataAdminBundle,jordisala1991/SonataAdminBundle,peter-gribanov/SonataAdminBundle,greg0ire/SonataAdminBundle,peter-gribanov/SonataAdminBundle,OskarStark/SonataAdminBundle,jordisala1991/SonataAdminBundle,mweimerskirch/SonataAdminBundle,mweimerskirch/SonataAdminBundle,jordisala1991/SonataAdminBundle,osavchenko/SonataAdminBundle,ossinkine/SonataAdminBundle,greg0ire/SonataAdminBundle,Armstrong1992/SonataAdminBundle,dmarkowicz/SonataAdminBundle,greg0ire/SonataAdminBundle