fix Default Filters tree scrolling
fix Default Filters tree scrolling

https://bugzilla.redhat.com/show_bug.cgi?id=1291748
(transferred from ManageIQ/manageiq@fb5f0fe7bd9556d32f3a655993e9779c043d271f)

ManageIQ/manageiq-ui-classic,ManageIQ/manageiq-ui-classic,ManageIQ/manageiq-ui-classic,ManageIQ/manageiq-ui-classic