package/matchbox: forcibly disable gconf

Buildroot does not have a gconf package, so explicitly disable gconf
support (to avoid it ends up picking the host one).

Reported-by: Arnout Vandecappelle <arnout@mind.be>
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Reviewed-by: Arnout Vandecappelle <arnout@mind.be>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

package/matchbox/matchbox.mk

@@ -11,7 +11,7 @@ MATCHBOX_LICENSE = GPLv2+
 MATCHBOX_LICENSE_FILES = COPYING
 
 MATCHBOX_DEPENDENCIES = matchbox-lib
-MATCHBOX_CONF_OPTS = --enable-expat
+MATCHBOX_CONF_OPTS = --enable-expat --disable-gconf
 
 # Workaround bug in configure script
 MATCHBOX_CONF_ENV = expat=yes