zstd: fix package source

It looks like GitHub changed the URL path for release tarballs, thus the
download for the zstd package was always falling back to the OpenWrt
sources mirror.

Fix the GitHub URL for one which works. The file hash remains unchanged.

Signed-off-by: David Bauer <[email protected]>

tools/zstd/Makefile

@@ -4,7 +4,8 @@ PKG_NAME:=zstd
 PKG_VERSION:=1.4.4
 
 PKG_SOURCE:=$(PKG_NAME)-$(PKG_VERSION).tar.gz
-PKG_SOURCE_URL:=@GITHUB/facebook/zstd/releases/download/v$(PKG_VERSION)
+PKG_SOURCE_URL_FILE:=v$(PKG_VERSION).tar.gz
+PKG_SOURCE_URL:=https://github.com/facebook/zstd/archive/
 PKG_HASH:=a364f5162c7d1a455cc915e8e3cf5f4bd8b75d09bc0f53965b0c9ca1383c52c8
 
 PKG_LICENSE:=BSD-3-Clause