允许换绑微信号

application/api/controller/User.php

@@ -717,7 +717,7 @@ class User extends Api
         }
 
         if(!empty($this->auth->wechat_openid)){
-            $this->error('已经绑定了微信号');
+            //$this->error('已经绑定了微信号');
         }
 
         $otherUserWhere['wechat_openid'] = $wechat_openid;