sip: bump MNCC version sent to sipcon to 6

Match commit Iaca9ed6611fc5ca8ca749bbbefc31f54bea5e925 in osmo-sip-connector.

Change-Id: I39d55432776926a385e1b85b21bcdea8180a8946
diff --git a/library/MNCC_Emulation.ttcn b/library/MNCC_Emulation.ttcn
index 9522e72..be087ec 100644
--- a/library/MNCC_Emulation.ttcn
+++ b/library/MNCC_Emulation.ttcn
@@ -38,7 +38,7 @@
 import from UD_Types all;
 
 modulepar {
-	int mp_mncc_version := 5;
+	int mp_mncc_version := 6;
 }
 
 /* General "base class" component definition, of which specific implementations