fix conversation result usage in loadEntireConversation

In loadEntireConversation, json was an array of [result, request], now it only takes result into account

WhatsAppWeb.Query.js

@@ -102,7 +102,7 @@ module.exports = {
 
         const loadMessage = () => {
             return this.loadConversation(jid, chunkSize, offsetID, mostRecentFirst)
-            .then (json => {
+            .then (([json]) => {
                 if (json[2]) {
                     // callback with most recent message first (descending order of date)
                     let lastMessage
@@ -201,4 +201,4 @@ module.exports = {
         const json = ["query", "inviteCode", jid]
 		return this.query (json).then (([json, _]) => json.code)
 	}
-}
+}