appimaged gets launched too often on Deepin Linux

[probonopd]

This should not happen.

We need to find out why it happens.

cc @shouhuanxiaoji

[probonopd]

Theory of operation:

• When the user downloads the appimaged AppImage from https://github.com/probonopd/go-appimage/releases/tag/continuous and double clicks, then it installs a per-user systemd unit file, and quits itself
• The per-user systemd unit file then launches the appimaged AppImage and keeps it running all the time

Something must be going wrong, but I do not know yet what.