ns: add test case TC_tx_blocked_foreign_nsvc

Check if a BLOCK PDU over a different/foreign connection is parsed.
* 2x initialize NSVC (RESET/UNBLOCK)
* TTCN  0-> NS: block (nsvci 1)
* TTCN  <-0 NS: block ack (nsvci 1)
* TTCN  1-> NS: unit data (nsvci 1)
* TTCN  <-1 NS: status (blocked)

Change-Id: I2b37a712bd70037b35b9deb8dab4a72d1e1d29fb
diff --git a/ns/osmo-ns.udp.cfg b/ns/osmo-ns.udp.cfg
index 9591427..b327c32 100644
--- a/ns/osmo-ns.udp.cfg
+++ b/ns/osmo-ns.udp.cfg
@@ -91,5 +91,9 @@
  bind udp local
   listen 127.0.0.1 23000
   accept-ipaccess
+ bind udp local2
+  listen 127.0.0.1 23001
+  accept-ipaccess
  nse 1234
   nsvc ipa local 127.0.0.1 22000 nsvci 1234
+  nsvc ipa local2 127.0.0.1 22001 nsvci 1235