[DL]String additions to 'mutter.master'

[GNOME Status Pages <noreply gnome org>]

This is an automatic notification from status generation scripts on:
https://l10n.gnome.org.

There have been following string additions to module 'mutter.master':

+ "Add persistent virtual monitor (WxH or WxH@R)"
    + "Run as a headless display server"

Note that this doesn't directly indicate a string freeze break, but it
might be worth investigating.
https://gitlab.gnome.org/GNOME/mutter/commits/master