AMR->IuUP: do not crash on AMR data before IuUP Init

When translating AMR to IuUP, when AMR data arrives before the IuUP side
has negotiated an IuUP Initialization, do not crash osmo-mgw, but return
failure and drop the AMR packet.

As soon as IuUP Initialization occured and RFCIs are defined, the AMR
starts to pass through to the IuUP side.

Related: SYS#5092
Change-Id: Id9efb7e523d8d9af988e4bf4f5e925839204f934
1 file changed