IPA sudo tests worked under the assumption that the clients
that are executing the sudo commands have their IPs assigned
within 255.255.255.0 hostmask.
Removes this (invalid) assumption and adds a
dynamic detection of the hostmask of the IPA client.
https://fedorahosted.org/freeipa/ticket/5501
Reviewed-By: Lukas Slebodnik <lslebodn@redhat.com>
Reviewed-By: Oleg Fayans <ofayans@redhat.com>
Reviewed-By: Ales 'alich' Marecek <amarecek@redhat.com>