msc: Accept optional f_init_handler() argument for Tguard

Some tests may want an extended guard timer as they're waiting for
some particularly slow events.  They can override the default now.

Change-Id: Iee6f50559a8fe45c7655b9f41e7fa163199b39a6
diff --git a/msc_tests/BSC_ConnectionHandler.ttcn b/msc_tests/BSC_ConnectionHandler.ttcn
index 843197e..97c02b8 100644
--- a/msc_tests/BSC_ConnectionHandler.ttcn
+++ b/msc_tests/BSC_ConnectionHandler.ttcn
@@ -62,11 +62,11 @@
 }
 
 /* init function, called as first function in new BSC_ConnHdlr */
-function f_init_handler(BSC_ConnHdlrPars pars) runs on BSC_ConnHdlr {
+function f_init_handler(BSC_ConnHdlrPars pars, float t_guard := 60.0) runs on BSC_ConnHdlr {
 	/* make parameters available via component variable */
 	g_pars := pars;
 	/* Start guard timer and activate it as default */
-	g_Tguard.start;
+	g_Tguard.start(t_guard);
 	activate(as_Tguard());
 }