Commit
8393632678762abfb08c827ce83629844bbcb727
by Oliver Smithupf_gtp: automatically clean old gtp devices
If osmo-upf crashes without running the destructor, we may have a
leftover gtp device. This can be simulated with "killall -9 osmo-upf".
Clean it up automatically.
Related: SYS#7240
Depends: libgtpnl Ib99bd8eed854014a5c9118c23e4058a41f3145f2
Change-Id: I7bb5c1ed51f4e05964688ee77b8de77fd3c0f345