update:code为0的条件优化

src/Mon/MonUtil.php

@@ -70,7 +70,7 @@ class MonUtil{
             }
 
             //接口返回状态码打点
-            if(!empty($code) && is_numeric($code)){
+            if(isset($code) && is_numeric($code)){
                 $result = self::counting($module . "." . (string)$request_uri, (string)$code,1) . "\n";
             }else{
                 $result = self::counting($module . "." . (string)$request_uri, (string)-999,1) . "\n";