#4918 (ok 4.4.8) Date field popup dialog position bug

Hi,

I found small bug in UI, see attached screenshots:
1. editing date field with dialog fully on a screen, looks OK, I can see NULL check box;
2. editing another date field, but here dialog partially out of screen and it shown over check box;
3. of course I can press cancel button to see check box, but it is annoying to do that many times.

[Atul Pratap Singh]

Fix: https://github.com/phpmyadmin/phpmyadmin/pull/1688