Fix 1.6-* upgrade to 1.7.1

8e72e521 (v1.7.1.2+) introduced a bug where
osTicket version 1.6 would not send a cookie (by calling PHP
session_start()) for the login page. Therefore, after unpacking the 1.7.1
source code, an upgrade would not be possible, because a login would never
be processed correctly.

include/class.ostsession.php

@@ -25,7 +25,12 @@ class osTicketSession {
         if(!$this->ttl)
             $this->ttl=SESSION_TTL;
 
-        if (defined('DISABLE_SESSION') || OsticketConfig::getDBVersion())
+        session_name('OSTSESSID');
+
+        if (OsticketConfig::getDBVersion())
+            return session_start();
+
+        elseif (defined('DISABLE_SESSION'))
             return;
 
         # Cookies
@@ -54,7 +59,6 @@ class osTicketSession {
         register_shutdown_function('session_write_close');
 
         //Start the session.
-        session_name('OSTSESSID');
         session_start();
     }