MT#56068 /api/resellerbrandings/:id change

* :id is now the brainding's id instead of reseller_id.
  That was rather a bug and now fixed and consistent with
  the rest of the endpoints.

Change-Id: I794e577499050a95ed68c21af3f963f9f8e9c274

lib/NGCP/Panel/Role/API/ResellerBrandings.pm

@@ -69,7 +69,8 @@ sub _item_rs {
 
 sub item_by_id {
     my ($self, $c, $id) = @_;
-    return $self->item_rs($c)->search_rs({'reseller.id' => $id})->first;
+    my $item_rs = $self->item_rs($c);
+    return $item_rs->find($id);
 }
 
 sub resource_from_item {