Changes

SGSN: TC_attach_gmm_attach_req_while_gmm_attach: fix test case

The SGSN has changed the behavior:
- removed auth-policy - not supported anymore
- require authentication
- remove ID Req(IMEI), not used by new libvlr SGSN

Change-Id: I026499844940d4c3d82b0fbd61be636c6ca348e6