dir permission improve

plugins/Common.php

@@ -541,6 +541,9 @@ Class Common {
         );
         $jsonData = json_encode($cacheData, JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE);
         $cacheDir = __DIR__ . '/../runtime/cache/';
+        if (!is_dir($cacheDir)) {
+            mkdir($cacheDir, 0777, true);
+        }
 
         //子目录支持
         if (!empty($cacheSubDir)) {