Rename this file, it causes a conflict:

https://bugs.gentoo.org/980039

--- a/data/Makefile.am
+++ b/data/Makefile.am
@@ -5,7 +5,7 @@
 dist_conf_DATA = lightdm.conf users.conf keys.conf
 
 dbusconfdir = $(datadir)/dbus-1/system.d
-dist_dbusconf_DATA = org.freedesktop.DisplayManager.conf
+dist_dbusconf_DATA = org.freedesktop.lightdm.conf
 
 pamdir = $(sysconfdir)/pam.d
 dist_pam_DATA = pam/lightdm \
