Elements menu can't fit in all items despite space beneath.

Prereq.: Demo installation with yoochoose license (to have all the blocks).

Steps:
1. Go to Page.
2. Create new Landing Page.
3. Examine the Elements menu on the right.
Actual: Last item at the bottom (RSS) is not fully visible, extra scrollbar is displayed (screenshot attached).
Expected: View height is dynamically adjusted to the number of items (there is spare space beneath).