PCU: fix: actually match IMSI in Packet Paging Request

Change-Id: I0afdd53fd5d2a89e139f65a7aec412a2e12511cc
diff --git a/library/L3_Templates.ttcn b/library/L3_Templates.ttcn
index 0556c97..6b5f5c2 100644
--- a/library/L3_Templates.ttcn
+++ b/library/L3_Templates.ttcn
@@ -2833,6 +2833,9 @@
 external function enc_MobileIdentityLV(in MobileIdentityLV si) return octetstring
 	with { extension "prototype(convert) encode(RAW)" };
 
+external function dec_MobileIdentityV(in octetstring mi) return MobileIdentityV
+	with { extension "prototype(convert) decode(RAW)" };
+
 
 
 /* SMS TPDU Layer */