Changes

ttcn3-epdg-test: fix osmo-epdg path for latest

Restore the proper path for osmo-epdg when running with -latest, which
has been removed by accident in the earlier commit that should only
have changed the config.

Fix for:
/data/epdg.sh: line 14: /tmp/osmo-epdg/_build/default/bin/osmo-epdg: No such file or directory

Fixes: 00e68245 ("ttcn3-epdg-test: remove latest code path")
Change-Id: I0547f62a3610a62e90ad767f447c68851e8a725d