Autostart feature just starts Electron

Description:

As reported upstream enabling the autostart feature in the client options makes a .desktop file being created at client startup, which just starts a vanilla Electron instance on a subsequent restart of the desktop environment. Upstream acknowledged the issue but if I'm correct this might stem from how the client is started in Arch.

Additional info:

• package version(s): mattermost-desktop 5.7.0-2
• config and/or log files:
• link to upstream bug report, if any: https://github.com/mattermost/desktop/issues/3029

Steps to reproduce:

1. Install the client, start it, enable the autostart features in the options and close it.
2. Restart the client: a .config/autostart/electron.desktop file is created
3. Restart the desktop environment: a vanilla Electron window is started instead of the Mattermost client.