Add support for ELECOM WRC-X3000GS2 to update "bootdelay" variable configured as "0" by default when sysupgrade. Signed-off-by: INAGAKI Hiroshi <musashino.open@gmail.com> Link: https://github.com/openwrt/openwrt/pull/18543 Signed-off-by: Robert Marko <robimarko@gmail.com>