busybox: fix build on musl.

srcpkgs/busybox/template

@@ -29,6 +29,12 @@ pre_build() {
 		make -C $t CFLAGS="$(_cflags $t)" KBUILD_SRC=${wrksrc}/src \
 			-f ${wrksrc}/src/Makefile defconfig
 		cp -f ${FILESDIR}/${t}.dotconfig ${t}/.config
+			
+		case "$XBPS_TARGET_MACHINE" in
+		*-musl) sed -i -e /CONFIG_FEATURE_VI_REGEX_SEARCH/s/y/n/ \
+				-e /CONFIG_FEATURE_MOUNT_NFS/s/y/n/ \
+				${t}/.config;;
+		esac
 
 		if [ "$CROSS_BUILD" ]; then
 			sed -e \