Fix token validation function in download handler

- Changed from dol_verifyToken() to checkToken()
- dol_verifyToken() doesn't exist in this Dolibarr version
- checkToken() is the correct function for token validation
- Should resolve the PHP Fatal error

download_pdf.php

@@ -30,7 +30,7 @@ $declaration_id = GETPOST('id', 'int');
 $token = GETPOST('token', 'alpha');
 
 // Validate token
-if (!dol_verifyToken($token)) {
+if (!checkToken($token)) {
     accessforbidden();
 }