Regression: Choose image doctype problem when adding an image document

Steps to follow:

1. create a new custom imageset [1]
2. in the cms, create a new folder in Image gallery tab
3. go in the console and find the created folder inside /document/gallery
4. the property hippostd:gallerytype is multiple, configure it to have the two imagesets available i.e. the default one (hippogallery:imageset) and the new created imageset
5. now you can go in the cms and create a new imageset, an additional dropdown will show in the first dialog where you can choose between the two types

The bug is in the created document, it will always create a imageset using the type in the first position of the dropdown no matter what choice you make

[1] http://www.onehippo.org/library/concepts/images-and-assets/create-a-custom-image-set.html