toolchain/fortify-headers: update download url
Development of fortify-headers has been moved to GitHub.
Gentoo [1] and Alpine Linux [2] already uses it.
Since updating fortify-headers to new version causes a lot of
compile errors, this commit does not bump version.
This commit also refresh patch.
[1]: https://packages.gentoo.org/packages/sys-libs/fortify-headers
[2]: https://git.alpinelinux.org/aports/log/main/fortify-headers
Signed-off-by: Yanase Yuki <dev@zpc.st>
Link: https://github.com/openwrt/openwrt/pull/16374
Signed-off-by: Robert Marko <robimarko@gmail.com>