rxvt-unicode: add x11 DISTRO_FEATURE check

rxvt is a classic X11 application, so add the feature check so it doesn't
get pulled into world builds without x11.

(From OE-Core rev: 3530b250e32fb0f164899d60019633d2ecf8ef67)

Signed-off-by: Ross Burton <ross.burton@arm.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/recipes-sato/rxvt-unicode/rxvt-unicode.inc

@@ -13,7 +13,9 @@ SRC_URI = "http://dist.schmorp.de/rxvt-unicode/Attic/rxvt-unicode-${PV}.tar.bz2
 	   file://rxvt.desktop \
 	   file://rxvt.png"
 
-inherit autotools pkgconfig update-alternatives
+inherit autotools features_check pkgconfig update-alternatives
+
+REQUIRED_DISTRO_FEATURES = "x11"
 
 RPROVIDES:${PN} = "virtual-x-terminal-emulator"
 ALTERNATIVE:${PN} = "x-terminal-emulator"