"This Location has no Sub-items" message is displayed above location.

Steps:

1. Install a fresh copy of e.g. Platform OSS master or 2.5.
2. Go to Content / Content structure.
3. Select eZ Platform folder.
4. Notice the layout on Content Tree.

Actual: The "This Location has no Sub-items" message is displayed above the location.
Expected: The message is displayed beneath the location.

Remarks: Relates to EZP-31367.