user/zstd: -> system, bump to 1.4.2

user/zstd/APKBUILD → system/zstd/APKBUILD

 # Contributor: A. Wilcox <awilfox@adelielinux.org>
 # Maintainer: A. Wilcox <awilfox@adelielinux.org>
 pkgname=zstd
-pkgver=1.4.0
+pkgver=1.4.2
 pkgrel=0
 pkgdesc="Fast real-time compression algorithm"
 url="https://facebook.github.io/zstd/"
@@ -24,4 +24,4 @@ package() {
 	make PREFIX="/usr" DESTDIR="$pkgdir" install
 }
 
-sha512sums="ef6d95639593fed3cfb9ff4f1527c4ba38658e42f16eb3369b2a4bbe150905751bb71c6e3fe9c8bbdfceee26a540ae3e41bd0f0bc692d36db444b7da65a6e304  zstd-1.4.0.tar.gz"
+sha512sums="b760f201ff8d018c422b030d3f59245b5f1cfd157ba8d6eb9fe9240e23d5739ca7b5a705b2d5e8ace703d041ab77bea66d735b283e51facfb18923794fabe213  zstd-1.4.2.tar.gz"