Add --domain option to ipa-client-automount for DNS discovery
If the client machine is not in the IPA DNS domain then discovery
will not find a server. Add a --domain option so that the set of
servers can be discovered.
Note that --domain is initialized to "" rather than None to match
the behavior in ipa-client-install.
Fixes: https://pagure.io/freeipa/issue/9780
Signed-off-by: Rob Crittenden <rcritten@redhat.com>
Reviewed-By: David Hanina <dhanina@redhat.com>