BUG 10052 Problema al realizar instalacion de cero en tetsing.2 SOLVED

- Missing validation whhit PATH_DATA constant in new function isPMUnderUpdating
- Add validation when PATH_DATA doesn' exists

gulliver/system/class.g.php

@@ -5081,6 +5081,9 @@ class G
     */
     public function isPMUnderUpdating($setFlag = 2)
     {
+        if (!defined('PATH_DATA')) {
+            return false;
+        }
         $fileCheck = PATH_DATA."UPDATE.dat";
         if ($setFlag == 0) {
             if (file_exists($fileCheck)) {