Whenever I press Super+L (or Win+L) on my Ubuntu 14.04 Desktop, the screen gets locked. I would like to disable this behaviour. In System Settings->Keyboard->Shortcuts->System there is a shortcut configured for Lock screen: Ctrl+Alt+L. It works. But I couldn't find where the shortcut for Super+L is configured.
Background: I run Ubuntu in a virtual machine on Windows and use Super+L to lock the Windows desktop, making it superfluous to lock the Ubuntu Desktop. Once I unlock the screen I have to type my password twice: Once for Windows and again for Ubuntu.
Unity also has a shortcut to lock the screen, so you need to disable that one too.