Changed the position of config file provided by upstream.
The config file provided by upstream was moved.
It originally resided under /usr/share/lxqt/
It preceded the one under /etc/xdg/xdg-Lubuntu/lxqt
So it was moved to /etc/xdg-Lubuntu/lxqt/globalkeyshortcuts.conf
It will be modified as needed by lubuntu-default-settings
Test Plan: Check if the shortcuts work according to P38
Reviewers: tsimonq2, wxl
Reviewed By: tsimonq2, wxl
Maniphest Tasks: T59
Differential Revision: https://phab.lubuntu.me/D38