broadway-server.c: Fix incoming connection callback
The callback to handle incoming connections does not follow the documentation, one argument is missing.
See: https://developer.gnome.org/gio/stable/GSocketService.html#GSocketService-incoming
The callback to handle incoming connections does not follow the documentation, one argument is missing.
See: https://developer.gnome.org/gio/stable/GSocketService.html#GSocketService-incoming