Fix bottom margin of Qt version options

Make the layout similar to the kit, compiler and debugger  option panes.

Task-number: QTCREATORBUG-11381
Change-Id: Ibed61fdc8257f6180eb921dce4dbd1ecd516291d
Reviewed-by: Daniel Teske <daniel.teske@digia.com>
Blackberry: fix warning

Change-Id: Iae5722540eca6d586deb721a1592848570580b88
Reviewed-by: Tobias Hunger <tobias.hunger@digia.com>