devel/glib20: unbreak session bus autolaunch after fcf0cc11

$ pkg install gtk4
$ service dbus onestart
$ cat /var/lib/dbus/machine-id
123456789012345678901234567890123
$ unset DBUS_SESSION_BUS_ADDRESS XDG_RUNTIME_DIR
$ gtk4-demo
(gtk4-demo:1234): Gtk-WARNING **: Unable to acquire session bus: Cannot spawn a message bus without a machine-id: Unable to load /var/local/lib/dbus/machine-id or /etc/machine-id: Failed to open file “/var/local/lib/dbus/machine-id”: No such file or directory
^C
$ gdbus call --session --dest=org.freedesktop.DBus --object-path=/ --method=org.freedesktop.DBus.ListNames
Error connecting: Cannot spawn a message bus without a machine-id: Unable to load /var/local/lib/dbus/machine-id or /etc/machine-id: Failed to open file “/var/local/lib/dbus/machine-id”: No such file or directory

Reported by:	vermaden

devel/glib20/Makefile

 PORTNAME=	glib
 DISTVERSION=	2.76.4
+PORTREVISION=	1
 PORTEPOCH=	2
 CATEGORIES=	devel
 MASTER_SITES=	GNOME
@@ -29,6 +30,7 @@ MESON_ARGS=	-Db_lundef=false \
 		-Ddefault_library=both \
 		-Dinstalled_tests=false \
 		-Dlibmount=disabled \
+		-Dlocalstatedir=/var \
 		-Druntime_dir=/var/run \
 		-Dselinux=disabled \
 		-Dxattr=false