RSL_Types: tr_RSL_MsgType() now accepts template as message discriminator

... avoids tiresome valueof() at every caller site
diff --git a/library/RSL_Types.ttcn b/library/RSL_Types.ttcn
index d9d91e4..52e4063 100644
--- a/library/RSL_Types.ttcn
+++ b/library/RSL_Types.ttcn
@@ -531,7 +531,7 @@
 	external function dec_RSL_Message(in octetstring stream) return RSL_Message
 		with { extension "prototype(convert) decode(RAW)" };
 
-	template RSL_Message tr_RSL_MsgType(RSL_MessageDiscriminator m_disc,
+	template RSL_Message tr_RSL_MsgType(template RSL_MessageDiscriminator m_disc,
 				RSL_MessageType m_type) := {
 		msg_disc := m_disc,
 		msg_type := m_type,