Policy editor: only redraw flash on error.
Policy editor: only redraw flash on error.

Do not redraw the whole form when an error occurs in the form to prevent
double flash message display.

Fixes:
https://bugzilla.redhat.com/show_bug.cgi?id=1501153

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