Rebame Excursion -> Guided City Walk in invoice

Change-Id: I33e712a15dc1b21f0e26153d0cc59d0ad12ab923
diff --git a/invoice.php b/invoice.php
index 7c7d5e2..d262a97 100644
--- a/invoice.php
+++ b/invoice.php
@@ -72,7 +72,7 @@
 
     if ($user->excursion) {
         $vat_sum += $EXCURSION * $FULL_VAT;
-        $invoice->addItem('Excursion', 'The excursion takes place on the afternoon 21 July.', 1, false, $EXCURSION, $EXCURSION * $FULL_VAT, $EXCURSION);
+        $invoice->addItem('Guided City Walk', 'The Guided City Walk takes place in the late afternoon of 21 July.', 1, false, $EXCURSION, $EXCURSION * $FULL_VAT, $EXCURSION);
     }
 
     /* Add totals */