Investigation suggests that the Firefox certificate validation
failure we sometimes get when loading the FreeIPA web UI in the
freeipa_webui test module is a race issue in Firefox itself:
https://bugzilla.mozilla.org/show_bug.cgi?id=1530429
refreshing the page seems to work around the problem, so let's
do that.
Signed-off-by: Adam Williamson <awilliam@redhat.com>