sgsn: reset encryption in SGSN_Tests_Iu.f_vty_config()

Ensure the expected default UEA configuration, which is always
reset properly even if one of the testcases aborts due to a DTE.

Change-Id: Ic2c5a11e86e4349796fa7508076ac27ef22815cd
diff --git a/sgsn/SGSN_Tests_Iu.ttcn b/sgsn/SGSN_Tests_Iu.ttcn
index f6a4243..5f1bb55 100644
--- a/sgsn/SGSN_Tests_Iu.ttcn
+++ b/sgsn/SGSN_Tests_Iu.ttcn
@@ -14,6 +14,9 @@
 private function f_init() runs on test_CT {
 	g_ranap_enable := true;
 	SGSN_Tests.f_init();
+
+	/* default VTY configuration */
+	f_vty_config(SGSNVTY, "sgsn", "encryption uea 0");
 }
 
 private function f_TC_iu_attach(charstring id) runs on BSSGP_ConnHdlr {
@@ -59,7 +62,6 @@
 	f_sleep(1.0);
 	vc_conn := f_start_handler(refers(f_TC_iu_attach), testcasename(), g_gb, 1001, expect_ciph := true);
 	vc_conn.done;
-	f_vty_config(SGSNVTY, "sgsn", "encryption uea 0");
 	f_cleanup();
 }