Remove check for hardcoded Xorg path in gdm.

diff --git a/daemon/gdm-local-display-factory.c b/daemon/gdm-local-display-factory.c
index ad2e65cf7..84637d1ef 100644
--- a/daemon/gdm-local-display-factory.c
+++ b/daemon/gdm-local-display-factory.c
@@ -272,7 +272,7 @@ struct GdmDisplayServerConfiguration {
         { "wayland", GDM_KEY_WAYLAND_ENABLE, NULL, "wayland" },
 #endif
 #ifdef ENABLE_X11_SUPPORT
-        { "xorg", GDM_KEY_XORG_ENABLE, "/usr/bin/Xorg", "x11" },
+        { "xorg", GDM_KEY_XORG_ENABLE, NULL, "x11" },
 #endif
         { NULL, NULL, NULL },
 };