mon: MonMap: do not increase mon_info_t's compatv in stretch mode, for real

mon: MonMap: do not increase mon_info_t's compatv in stretch mode, for real

This was supposed to be fixed a year ago in commit
2e3643647bfbe955b54c62c8aaf114744dedb86e, but it set compat_v to 4 instead of all
the way back to 1 as it should have.

Our testing for stretch mode in these areas is just not very thorough -- the
kernel only supports compat_v 1 and apparently nobody's noticed the issue
since then? :/
As the prior commit says, you can't set locations without being gated on a
server feature bit, so simply cancelling this enforcement is completely safe.

Fixes: https://tracker.ceph.com/issues/53237
Signed-off-by: Greg Farnum <gfarnum@redhat.com>
(cherry picked from commit ccb1b7eb8baf5f222109e77c168db39e699b6934)