feat：修复设置杠杆错误

@@ -98,7 +98,7 @@ class Api
         $header = [];
         $body = '';
         $fullPath = $path;
-        $timestamp = getMicrotime() * 1000;
+        $timestamp = getMicrotime();
 
         if ($method == 'GET' && !empty($param)) {
             $fullPath = $path . '?' . http_build_query($param);