sgsn_libgtp: fix a potential memleak when the GGSN is not reachable

When a MS does the following

- MS: GMM Attach
- MS: Activate PDP CTX
- SGSN: send PDP CTX Request to GGSN which GGSN does not answer
- GMM Detach (MM ctx get freed)
- libgtp retrans timeout of the first answer
- sgsn_libgtp.c: create_pdp_conf() which ignores this ctx because of emtpy MM ctx

Change-Id: I4575f7f80f785a62ae3b7f165d236a9dd818aabf
1 file changed