Enable GSMTAP on BTS and record it on the main unit NITB

Change-Id: I057a83bc20c5e664ac1778812452f189166919ba
diff --git a/src/osmo_gsm_tester/bts_sysmo.py b/src/osmo_gsm_tester/bts_sysmo.py
index 1c36fb8..771d303 100644
--- a/src/osmo_gsm_tester/bts_sysmo.py
+++ b/src/osmo_gsm_tester/bts_sysmo.py
@@ -78,7 +78,8 @@
             remote_binary = self.remote_inst.child('bin', 'osmo-bts-sysmo')
             self.launch_remote('osmo-bts-sysmo',
                 ('LD_LIBRARY_PATH=%s' % remote_lib,
-                 remote_binary, '-c', remote_config_file, '-r', '1'),
+                 remote_binary, '-c', remote_config_file, '-r', '1',
+                 '-i', self.nitb.addr()),
                 remote_cwd=remote_run_dir)
 
     def _process_remote(self, name, popen_args, remote_cwd=None):