add set debug mode

Author: KenChoi

android/src/io/jchat/android/Constant.java

@@ -1,7 +1,7 @@
 package io.jchat.android;
 
 public class Constant {
-
+    static final String ENABLE = "enable";
     public static final String USERNAME = "username";
     public static final String PASSWORD = "password";
     public static final String OLD_PWD = "oldPwd";

android/src/io/jchat/android/JMessageModule.java

@@ -137,6 +137,16 @@ public void init(int mode) {
 
     }
 
+    @ReactMethod
+    public void setDebugMode(ReadableMap map) {
+        try {
+            boolean enable = map.getBoolean(Constant.ENABLE);
+            JMessageClient.setDebugMode(enable);
+        } catch (Exception e) {
+            e.printStackTrace();
+        }
+    }
+
     /**
      * 启动应用时判断登录状态
      *