sgsn: add TC_attach_no_imei_response

Ignores Identity Request IMEI.

MS -> SGSN: Attach Request IMSI
MS <- SGSN: Identity Request IMSI (optional)
MS -> SGSN: Identity Response IMSI (optional)
MS <- SGSN: Identity Request IMEI
MS -x SGSN: no response
MS <- SGSN: re-send: Identity Request IMEI 4x
MS <- SGSN: Attach Reject

Change-Id: Ie50c75e62e31e01c5b17969fb067664e44fd68a5
1 file changed