popup: fix sizing eval logic when scrollable set TRUE
When scrollable set TRUE,
scroller must be calculated its size except using item.
If content is removed, scroller doesn't calculate its size, so it has previous size.
So there is a empty space in this case.
- elementary_test -to popup
- open "popup-center-title + list content + 2 button (with delete content)"
- click "Delete" button
- compare between scrollable set true and false
Reviewers: herb, singh.amitesh, jpeg, cedric, conr2d
Differential Revision: https://phab.enlightenment.org/D5010