MT#15837 mod_sipwise_vcard_cusax: add error when no info is retrive

This removes the lua error when trying to access nil value info.user

http://xmpp.org/rfcs/rfc6120.html#stanzas-error-conditions

Change-Id: Id5709fd4f2b234b6062a6f5433799d35fb90b7f3

plugins/mod_sipwise_vcard_cusax.lua

@@ -145,10 +145,21 @@ local function handle_vcard(event)
 			user = session.username;
 			host = session.host;
 		end
+		if not (user and host) then
+			module:log("error", "bad-request stanza: %s",
+				tostring(stanza))
+			session.send(st.error_reply(stanza, "modify", "jid-malformed"));
+		end
 		local info = vcard.get_subscriber_info(user, host);
-		local vCard = generate_vcard(info);
-		local reply = st.reply(stanza):add_child(st.deserialize(vCard));
-		session.send(reply);
+		if info then
+			local vCard = generate_vcard(info);
+			local reply = st.reply(stanza):add_child(st.deserialize(vCard));
+			session.send(reply);
+		else
+			module:log("error", "No info retrieve from stanza: %s",
+				tostring(stanza))
+			session.send(st.error_reply(stanza, "cancel", "item-not-found"));
+		end
 	else
 		module:log("debug", "reject setting vcard");
 		session.send(st.error_reply(stanza, "auth", "forbidden"));