Changes

nplab-m3ua-test: Configure Network Indicator as International

That's what we are using at the osmo-stp configuration.
Until now it didn't matter since libosmo-sigtran didn't validate NI
matching configuration on received messages, but since
1af56bf8cf266dd708b623e75d6d175a58f3dd47 it does.

Change-Id: Iae825ebc588524c7a3761c80392940733f3887a6