Fixed crash on add item via favorite button after application start.

Favorite buttons has short name labels.
closes #296
refs #293

shop/shop.json

@@ -8,7 +8,7 @@
         "default" : "",
         "CZ" : ""
     },
-    "schemaVersion" : 4,
+    "schemaVersion" : 5,
     "sql" : [
         "CREATE TABLE \"VoucherItem\" (
   \"id\" INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT,
@@ -70,6 +70,8 @@ CREATE TABLE \"Voucher\" (
   \"vatType\" INTEGER NOT NULL,
   \"pluginId\" TEXT NULL,
   \"favButtonName\" TEXT NULL);
+",
+    "ALTER TABLE \"FavoritItem\" ADD \"shortName\" TEXT NULL;
 "
     ],
     "dependencies" : [ "ADDRESSBOOK" ],