XDG_CONFIG_HOME is not respected

[eukara]

Description

Currently the Mumble client hard-codes the location of the Mumble config directory to be located at ~/.config/mumble when it should read the XDG_CONFIG_HOME environment instead.

https://github.com/mumble-voip/mumble/blob/f73db9da7ac81eda2c6eeacad6c97d97481a5e65/src/mumble/Database.cpp#L50

Steps to reproduce

1. Changing XDG_CONFIG_HOME and move ~/.config to set location.
2. Launch Mumble client.
3. Mumble will give an alert about the database file being missing.

Mumble version

1.4.0

Mumble component

Client

OS

Linux

Reproducible?

Yes

Additional information

No response

Relevant log output

No response

Screenshots

No response