mon: do not goto reply if a ruleset exists in pending

If the crush ruleset is found in pending, do not goto reply because it
does not exist yet. Wait for the pending proposal (and the ruleset) to
be accepted and then only return that it exists.

revert 4b687ba673574bcd3b77b0f79a07d5c74cdcedc2

Signed-off-by: Loic Dachary <loic@dachary.org>