package/xtables-addons: drop unrecognized option

--with-xtables is an unrecognized option since the addition of the
package in commit 4909173:
https://github.com/nawawi/xtables-addons/blob/a576f4d43e80f9f91705c9e6a86f2d58c283df14/configure.ac

configure: WARNING: unrecognized options: --disable-gtk-doc, --disable-gtk-doc-html, --disable-doc, --disable-docs, --disable-documentation, --with-xmlto, --with-fop, --enable-ipv6, --disable-nls, --with-xtables

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>

package/xtables-addons/xtables-addons.mk

@@ -13,7 +13,6 @@ XTABLES_ADDONS_LICENSE_FILES = LICENSE
 
 XTABLES_ADDONS_CONF_OPTS = \
 	--with-kbuild="$(LINUX_DIR)" \
-	--with-xtables="$(STAGING_DIR)/usr" \
 	--with-xtlibdir="/usr/lib/xtables"
 
 define XTABLES_ADDONS_BUILD_CMDS