Content view: duplicated message in "Filters" page when add/remove repositories
Cloned from https://bugzilla.redhat.com/show_bug.cgi?id=1092224
Description of problem:
After added/removed repositories, message "Content View updated." show up, keep it then go to "Filters" page, double message show up.
Version-Release number of selected component (if applicable):
Steps to Reproduce:
fixes #6686 - Remove extraneous alch-alert div from CV filters index
Both the Content View and Content View Filters views have an alch-alert
div, which causes alerts to be shown twice in some situations. The
Content View filters alch-alert is provided through the nutupane details
layout, and this PR provides a way to hide it.