Show version name in settings, fix progress bar when purchase ended wit error

lib/screens/purchase.dart

@@ -386,6 +386,9 @@ class PurchaseScreenState<T> extends BaseState<PurchaseScreen> {
         }
 
         if (purchase.containsKey('errors')) {
+          setState(() {
+            loading = false;
+          });
           List<String> errors = purchase['errors'];
           purchaseInProgress = false;
           apiErrorAlert(errors[0]);