Bug 14407: Follow up to add test case and clean noise

Bug 14407: Follow up to add test case and clean noise

Comment #28 has a /36 which is invalid CIDR.
This triggers a crash and noise.
This cleans up the crash and noise, and adds
test cases to check for them.

prove t/Auth.t
-- before missing null case, and /36 case.
-- after null case, and /36 with/without warnings.

Signed-off-by: Mark Tompsett <mtompset@hotmail.com>
Signed-off-by: Hayley Mapley <hayleymapley@catalyst.net.nz>
Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Signed-off-by: Nick Clemens <nick@bywatersolutions.com>