OSD: _share_map_outgoing whenever sending a message to a peer

This ensures that they get new maps before an op which requires them (that
they would then request from the monitor).

Signed-off-by: Greg Farnum <greg@inktank.com>
Merge pull request #1613 from ceph/wip-7994

OSD: _share_map_outgoing whenever sending a message to a peer

Reviewed-by: Sage Weil <sage@inktank.com>