package/xserver_xorg-server: disable unit tests

Fixes:
 - http://autobuild.buildroot.org/results/95a5004c9245f1f90758631b02e17d3df12812ec

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
(cherry picked from commit c41d8ba066125d4ae20f865e01c8143a5ff58a16)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/x11r7/xserver_xorg-server/xserver_xorg-server.mk

@@ -47,6 +47,7 @@ XSERVER_XORG_SERVER_CONF_OPTS = \
 	--disable-xnest \
 	--disable-xephyr \
 	--disable-dmx \
+	--disable-unit-tests \
 	--with-builder-addr=buildroot@buildroot.org \
 	CFLAGS="$(TARGET_CFLAGS) -I$(STAGING_DIR)/usr/include/pixman-1 -O2" \
 	--with-fontrootdir=/usr/share/fonts/X11/ \