Changes

ttcn3-epdg-test: restore osmo-epdg.latest.config

The osmo-epdg.latest.config is needed, as it has a different libdir:
-  {libdir, "/usr/lib"}
+  {libdir, "/tmp/osmo-epdg/_build/default/lib/gen_socket/priv/lib"}

Fix for:
Failed to load NIF library: '/tmp/osmo-epdg/_build/default/lib/gen_socket/priv/lib/gen_socket_nif.so: cannot open shared object file: No such file or directory'

Change-Id: Icb3e79d5f5ca9af67037c2746318d61fd2713967