fix an unhold issue during the failed 2nd outgoing call

Regression issue after removed duplicated indications for un-hold:

A and B in call;
B flash/R and dial some unavailable number and received congestion tone;
B flash/R again within the congestion tone period(5s, channel_state = CALLING).

then external channel(pjsip) on B unholded, but local channel on B keeps no changes due to the mismatching channel_state

If B flash/R again after the congestion tone period(channel_state: AWAITONHOOK), everything works okay.