abuild: do not add busybox as dep to busybox itself

abuild

@@ -285,7 +285,7 @@ size = $size
 EOF
 	local i deps
 	deps="$depends"
-	if [ -n "$install" ] && head -n 1 "$srcdir/$install" | grep '^#' >/dev/null && ! depends_has busybox ; then
+	if [ -n "$install" ] && head -n 1 "$srcdir/$install" | grep '^#' >/dev/null && ! depends_has busybox && [ "$pkgname" != "busybox" ]; then
 		msg "Adding busybox to depends since we have an install script"
 		deps="$deps busybox"
 	fi