Automatically send RESET to the MSC as the BSCNAT starts up. Try it
again if it fails, in case the MSC was not started yet or if the SCCP
connection was not up yet (right now it does not seem possible to get
notified when the SCCP connection is up).
Related: SYS#5560
Related: https://osmocom.org/projects/osmo-bscnat/wiki/AoIP_OsmoBSCNAT#RESET
Change-Id: Icfec3ec0168c7040e88a536fa48da339349fb6cf
