misc:kemi_lua append_hf to append

(cherry picked from commit 5ceb3b857d448fed1e819812dcb4a9724243cdb8)
(cherry picked from commit 1cac068d1acdd44081a1c4e65a317a4b208a08bb)

misc/examples/kemi/kamailio-basic-kemi-lua.lua

@@ -325,7 +325,7 @@ end
 function ksr_route_sipout()
 	if KSR.is_myself(KSR.pv.get("$ru")) then return 1; end
 
-	KSR.hdr.append_hf("P-Hint: outbound\r\n");
+	KSR.hdr.append("P-Hint: outbound\r\n");
 	ksr_route_relay();
 	KSR.x.exit();
 end