Disable middle click paste in Ubuntu 16.04

 Fedora 24 you can install gnome-tweak-tool using the following command:

$ sudo dnf install gnome-tweak-tool

Open gnome-tweak-tool and go to the "Keyboard and Mouse" tab and disable "Middle-click-Paste".

originally from https://unix.stackexchange.com/questions/24330/how-can-i-turn-off-middle-mouse-button-paste-functionality-in-all-programs