system/*: use useradd, groupadd instead of adduser, addgroup

system/abuild/APKBUILD

 # Maintainer: A. Wilcox <awilfox@adelielinux.org>
 pkgname=abuild
 pkgver=3.3.1
-pkgrel=1
+pkgrel=2
 pkgdesc="Script to build APK packages"
 url="https://code.foxkit.us/adelie/aports"
 arch="all"

system/abuild/abuild.pre-install

 #!/bin/sh
 
-addgroup -S abuild 2>/dev/null
+groupadd -r abuild 2>/dev/null
 
 exit 0

system/at/APKBUILD

@@ -2,7 +2,7 @@
 # Maintainer: A. Wilcox <awilfox@adelielinux.org>
 pkgname=at
 pkgver=3.1.23
-pkgrel=1
+pkgrel=2
 pkgdesc="Delayed job execution and batch processing daemon"
 url="https://packages.qa.debian.org/a/at.html"
 arch="all"

system/at/at.pre-install

 #!/bin/sh
 
-addgroup -S at 2>/dev/null
-adduser -S -D -H -s /bin/false -G at -g at at 2>/dev/null
+groupadd -r at 2>/dev/null
+useradd -c at -s /sbin/nologin -g at -r at 2>/dev/null
 
 exit 0

system/fcron/APKBUILD

@@ -2,7 +2,7 @@
 # Maintainer: A. Wilcox <awilfox@adelielinux.org>
 pkgname=fcron
 pkgver=3.2.1
-pkgrel=1
+pkgrel=2
 pkgdesc="periodical command scheduler for systems not always up"
 url="http://fcron.free.fr/"
 pkgusers="fcron"

system/fcron/fcron.pre-install

 #!/bin/sh
 
-adduser -S -D -H -s /sbin/nologin -g fcron fcron 2>/dev/null
-addgroup -S fcron 2>/dev/null
+groupadd -r fcron 2>/dev/null
+useradd -c fcron -s /sbin/nologin -g fcron -r fcron 2>/dev/null
 
 exit 0