edit

lib/Wechat.php

@@ -412,7 +412,8 @@ class Wechat
 				$config['param'][$k] = $param[$v];
 			} elseif($v) {
 				$config['param'][$k] = $this->replace($v, $param);
-			} else {
+			}
+			if ($config['param'][$k] == $k) {
 				unset($config['param'][$k]);
 			}
 		}