Changes

SGSN: TC_attach_auth_id_timeout: set TMSI to provoke a ID Request

This test case simulates a MS which ignores Identity Requests. To ensure
the SGSN will ask for the IMSI, do an Attach Request with id TMSI.
Later this ID Request (type IMSI) will be ignored and the test case
expect a Attach Reject.

Change-Id: I5a860582aa57ebc073e4c33f3f2f8884e360edef