Users with "Content/Edit, Limitation: Owner" security role are unable to use the UDW.

Steps to reproduce:

1. Setup clean latest eZ Platform installation.
2. Login to admin UI as the default admin user.
3. Create "Folder 1" and "Folder 2" folders under the root "eZ Platform" folder.
4. Create a new "Editor 2" security role: 

   Module	Function	Limitations
   Content	Read	None
   Content	Create	None
   Content	Edit	Owner: Self
   Url	All functions	None
   User	Login	None

1. Create a new "Editor 2" ** user group and assign the "Editor 2" role to it.
2. Create a new user in the "Editor 2" user group.
3. Login into admin UI as a new user (created on the previous step).
4. Click the "Create" button in the dashboard.
5. In the UDF select "eZ Platform" folder.

Expected result:

**"Folder 1" and "Folder 2" folders are shown in the UDW.

Actual result:

UDF breaks, and nothing is shown inside "eZ Platform" folder.