OSD: disable the PGStatsAck timeout when we are reconnecting to a monitor

OSD: disable the PGStatsAck timeout when we are reconnecting to a monitor

Previously, the timeout counter started as soon as we issued the reopen,
but if the reconnect process itself took a while, we might time out and
issue another reopen just as we get to the point where it's possible to
get work done. Since the mon client has its own reconnect timeouts (that is,
the OSD doesn't need to trigger those), we instead disable our timeouts
while the reconnect is happening, and then turn them back on again starting
from when we get the reconnect callback.

Signed-off-by: Greg Farnum <greg@inktank.com>