common/pick_address: Allow binding on loopback iface

common/pick_address: Allow binding on loopback iface

in 6147c0917157efd2d35610e759685656a4989abb, "lo" is also skipped when
daemon is trying to find an address to bind. but that change reverts the
fix of 201b59204374ebdab91bb554b986577a97b19c36, to address the problem.

an option named "ms_bind_exclude_lo_iface" is added, it defaults to
"true". but it can be changed to false to allow daemon to bind on "lo".

Fixes: https://tracker.ceph.com/issues/50012
Signed-off-by: Kefu Chai <kchai@redhat.com>
(cherry picked from commit 7f01d36a2ca0576f1ff103ae3fa7c3662e93b722)