bsc: fix missing vty exit in f_vty_allow_emerg_bts()

Without this, subsequent vty commands become "% Unknown command".

(Triggered by the test start vty "logp" in f_start_handler() that is going to
be added by subsequent patch.)

Change-Id: I51ace11883256ee0725caae46ea22adb2ea5eb39
diff --git a/bsc/BSC_Tests.ttcn b/bsc/BSC_Tests.ttcn
index 9109933..df4b45e 100644
--- a/bsc/BSC_Tests.ttcn
+++ b/bsc/BSC_Tests.ttcn
@@ -6847,6 +6847,7 @@
 	}
 	f_vty_transceive(BSCVTY, "exit");
 	f_vty_transceive(BSCVTY, "exit");
+	f_vty_transceive(BSCVTY, "exit");
 }
 
 /* Begin assignmet procedure and send an EMERGENCY SETUP (RR) */