Fix bug 4.4.4 spark not working

After upgrading 4.4.3 to 4.4.4 a bug are coming, spark not launching the CI with cmd. php spark server*

Error log: 

Undefined global variable $_SESSION

at SYSTEMPATH\Session\Session.php:499

Backtrace:
  1    SYSTEMPATH\Session\Session.php:499
       CodeIgniter\Debug\Exceptions()->errorHandler(2, 'Undefined global variable $_SESSION', 'C:\\wamp64\\www\\system\\Session\\Session.php', 499)

My fix working with no errors and launching correctly CI.

Author: ALTITUDE-DEV-FR

system/Session/Session.php

@@ -496,7 +496,7 @@ public function get(?string $key = null)
             return $value;
         }
 
-        if ($_SESSION === []) {
+        if (empty($_SESSION) || $_SESSION === []) {
             return $key === null ? [] : null;
         }