gscon_forget_lchan(): no Clear Request after Clear Command

Send a BSSMAP Clear Request only if we are not already in ST_CLEARING, i.e.
haven't received a BSSMAP Clear Command yet.

Related: osmo-ttcn3-hacks If772dbbc5f9790d3f911465e1303dd0a99811154
Change-Id: Idc749068580da45e821e0af04cfa14cc7ce5c432
1 file changed