IPA_Emulation: Add missing zero byte to strings in IPA CCM ID RESP

Change-Id: I3fdc0f47381d5ba1763197d5f264696f04d0396f
diff --git a/library/IPA_Emulation.ttcnpp b/library/IPA_Emulation.ttcnpp
index a271f2d..b10a983 100644
--- a/library/IPA_Emulation.ttcnpp
+++ b/library/IPA_Emulation.ttcnpp
@@ -239,7 +239,7 @@
 private template IpaCcmRespPart t_IdRespPart(IpaCcmIdTag tag, charstring payload) := {
 	len := 0,	/* overwritten by codec */
 	tag := tag,
-	data := payload
+	data := char2oct(payload) & '00'O
 }
 
 private function f_send_IPA_EVT(template ASP_IPA_Event evt) runs on IPA_Emulation_CT {