Image picker upload stores image at /content/gallery

When you upload a new image with the image picker used for rich text fields, the image can be uploaded to the path /content/gallery. This path is not accessable from the UI. It should be uploaded into a folder.

Reproduction steps:
1. Edit a document with a rich text field
2. Use the image picker to insert a image in the rich text
3. Use the option at the top of the picker dialog to choose and then upload a new image
4. Result: the image is uploaded to /content/gallery.
5. Effect: you can pick the image with the picker, and it shows up in the document and on the site, but if you go to the images section you cannot see it anymore. You only see the folder(s) on the /content/gallery level.