Changes

ttcn3-ggsn-ogs: Change diameter node id to pcrf

This better identifies the peer, specially since we'll also connect to
an OCS in the future.

Depends: osmo-ttcn3-hacks.git Change- Id I1eb03d907b46c4bb24491f390ef468e831190e08
Change-Id: I4c9f90de1456cf1515c9a0608b44a44fa8acb311