Summary: Removes hard requirement for xterm, which caused connection editing to fail. Test Plan: 1. Right click on nm-tray 2. Click "Edit Connections" If successful, qterminal will open, though the display will not be correct. Additional changes to lubuntu-default-settings are required, as described in the bug. Reviewers: tsimonq2 Reviewed By: tsimonq2 Differential Revision: https://phab.lubuntu.me/D3