Fix #5777 - rule interpolation broke auth.conf CIDR rules
Due to the interpolation performed to support regex back-references,
various type of rules (mainly IP CIDR notations and wildcard hosts)
were not working anymore.
This patch adds an auth.conf integration test that covers most
of the various rules types.
Signed-off-by: Brice Figureau <brice-puppet@daysofwonder.com>