OSD: relax monitor ping requirements while connecting
Right now, the OSD will time out a monitor after 30 seconds if it fails to ack a PGStats message. But sometimes, the monitor is responding (slowly) but the overall connection and authentication process itself takes almost 30 seconds, without the OSD actually transmitting the PGStats over the wire. This obviously hints at other problems in the cluster, but we should have a separately-tunable timeout for monitor connect and only start the PGStats timeout after the connection completes. This is probably best served by providing the MonClient a timeout for reconnects, and a callback for when the connection is complete.