GPRS: log NS socket

Let's log NS UDP socket creation similar to the way we log it for telnet
and ctrl interfaces.

Change-Id: Ic9d0f94ab2c1bb33f67cd4f1c9236b64108c0bb6
diff --git a/src/gb/gprs_ns.c b/src/gb/gprs_ns.c
index d20ed23..7443a8b 100644
--- a/src/gb/gprs_ns.c
+++ b/src/gb/gprs_ns.c
@@ -1580,6 +1580,7 @@
 			"Failed to set the DSCP to %d with ret(%d) errno(%d)\n",
 			nsi->nsip.dscp, ret, errno);
 
+	LOGP(DNS, LOGL_NOTICE, "NS UDP socket at %s:%d\n", inet_ntoa(in), nsi->nsip.local_port);
 
 	return ret;
 }