fix param

dev/examples/code/get_contracts.php

@@ -50,7 +50,7 @@ $langs->load("main");				// To load language file for default language
 // Load user and its permissions
 $result = $user->fetch('', 'admin');	// Load user for login 'admin'. Comment line to run as anonymous user.
 if (!$result > 0) {
-	dol_print_error('', $user->error);
+	dol_print_error(null, $user->error);
 	exit;
 }
 $user->getrights();