Update to the latest stable version. Also remove obsolete symbol
PKG_CONFIG_SYSROOT_DIR[1].
[1] 8ef8dee4f3
Signed-off-by: Shiji Yang <yangshiji66@outlook.com>
Link: https://github.com/openwrt/openwrt/pull/24123
Signed-off-by: Jonas Jelonek <jelonek.jonas@gmail.com>