Remove switch not present in newer uglifyjs versions
Remove repositioning on non-small displays.

Setting top:50% on larger displays was causing the modal to be too far down
the screen. Regular Bootstrap is fine for us on larger displays so removed this
section and it will only do stuff on smaller displays now.

Had attempted to upgrade the responsive modal plugin from upstream, but that had no
effect on the larger screen and broke the previously-working small screen behaviour,
hence this manual fix.