Allows vertical scrollbars to scroll down more by default 

In my OS by default, the scrollbars show like this:

Which is fine. However, when my mouse is near the last item, the scrollbar enlarges/become bigger and almost cover the last item 100%, making it very hard to select it:

I suggest allowing the scrollbar scroll down beyond the original limit:

So when the scrollbar enlarges, it does not hide the last item:

# cat /etc/os-release
NAME="Linux Mint"
VERSION="19.1 (Tessa)"
ID=linuxmint
ID_LIKE=ubuntu
PRETTY_NAME="Linux Mint 19.1"
VERSION_ID="19.1"
HOME_URL="https://www.linuxmint.com/"
SUPPORT_URL="https://forums.ubuntu.com/"
BUG_REPORT_URL="http://linuxmint-troubleshooting-guide.readthedocs.io/en/latest/"
PRIVACY_POLICY_URL="https://www.linuxmint.com/"
VERSION_CODENAME=tessa
UBUNTU_CODENAME=bionic