Changes

ttcn3-ggsn-test-ogs: set CAP_NET_RAW for open5gs-upfd

The SO_BINDTODEVICE feature (used for VRF) requires CAP_NET_RAW. Since
we run open5gs-upfd as user "osmocom", that seems to be causing some
permission problems under some systems (like jenkins). Let's make sure
we add the capabilitites to the binary before launching it as user
"osmocom".

Change-Id: I51ee6954a6c019a41cfcd50b2d99166316989d9b