osmotrx: Allow running osmo-trx from remote host

Change-Id: Ia31ac8eb41e02eda28d9f6f56774679300244ee8
diff --git a/src/osmo_gsm_tester/resource.py b/src/osmo_gsm_tester/resource.py
index e043d87..3f2ddc7 100644
--- a/src/osmo_gsm_tester/resource.py
+++ b/src/osmo_gsm_tester/resource.py
@@ -72,6 +72,7 @@
         'bts[].osmo_trx.type': schema.STR,
         'bts[].osmo_trx.clock_reference': schema.OSMO_TRX_CLOCK_REF,
         'bts[].osmo_trx.trx_ip': schema.IPV4,
+        'bts[].osmo_trx.remote_user': schema.STR,
         'bts[].osmo_trx.multi_arfcn': schema.BOOL_STR,
         'arfcn[].arfcn': schema.INT,
         'arfcn[].band': schema.BAND,