ns2: Don't automatically re-start FSM at FORCE_UNCONFIGURED

There are use cases in which the NS-VC FSM should go back to
unconfigured _without_ being re-started immediately.  Let's permit
the caller to do that.

Change-Id: I31fe695a83d38ea1f10f5444e840633d7fa68442
diff --git a/src/gb/gprs_ns2_vty.c b/src/gb/gprs_ns2_vty.c
index 5d0f5c0..a3aa6ee 100644
--- a/src/gb/gprs_ns2_vty.c
+++ b/src/gb/gprs_ns2_vty.c
@@ -1484,6 +1484,7 @@
 static int nsvc_force_unconf_cb(struct gprs_ns2_vc *nsvc, void *ctx)
 {
 	ns2_vc_force_unconfigured(nsvc);
+	ns2_vc_fsm_start(nsvc);
 	return 0;
 }