main/postmarketos-ui-xfce4: set XDG_RUNTIME_DIR (MR 1151)

 working towards #458. See [1] for an explaination

 [1]: https://gitlab.com/postmarketOS/pmaports/-/merge_requests/1131#note_318923711

main/postmarketos-ui-xfce4/APKBUILD

@@ -2,7 +2,7 @@
 # Maintainer: Daniele Debernardi <drebrez@gmail.com>
 pkgname=postmarketos-ui-xfce4
 pkgver=0.3
-pkgrel=0
+pkgrel=1
 pkgdesc="(X11) Lightweight GTK+2 desktop (stylus recommended)"
 url="https://gitlab.com/postmarketOS/xfce4-phone"
 arch="noarch"
@@ -10,7 +10,7 @@ license="GPL-3.0-or-later"
 depends="xfce4 xfce4-terminal xfce4-battery-plugin xfce4-pulseaudio-plugin xfce4-screensaver xfce4-whiskermenu-plugin
 	network-manager-applet xorg-server lightdm lightdm-openrc lxpolkit mesa-egl gnome-keyring
 	postmarketos-artwork-wallpapers postmarketos-artwork-icons faenza-icon-theme
-	pm-utils pavucontrol pulseaudio-utils"
+	pm-utils pavucontrol pulseaudio-utils elogind"
 install="$pkgname.post-install $pkgname.pre-deinstall $pkgname.post-deinstall $pkgname.post-upgrade"
 source="$pkgname-$pkgver.tar.gz::https://gitlab.com/postmarketOS/xfce4-phone/-/archive/$pkgver/xfce4-phone-$pkgver.tar.gz
 	60-lightdm-autologin.conf"