修改iOS Notification的总长度不超过2000字节

Author: caiyg

src/main/java/cn/jpush/api/push/model/PushPayload.java

@@ -30,7 +30,7 @@ public class PushPayload implements PushModel {
     private static final String SMS = "sms_message";
 
     private static final int MAX_GLOBAL_ENTITY_LENGTH = 4000;  // Definition acording to JPush Docs
-    private static final int MAX_IOS_PAYLOAD_LENGTH = 220;  // Definition acording to JPush Docs
+    private static final int MAX_IOS_PAYLOAD_LENGTH = 2000;  // Definition acording to JPush Docs
 
     private static Gson _gson = new Gson();