osmo-mgw.cfg syntax fix

was added with mismatching indent in

"mgw: Update to contain similar config from docker-playground.git"
commit cec73acdd4fa4ddc39ab44853ece0888b3e1bf34
I2aa4d86e548d6644f1dd9358f6b8b48a19c96c3c

Change-Id: I5d4d1af40410bfdcc1280f45b85a8ae0c7b94a80
1 file changed