main/amavisd-new: pre-install and existing user

pre-install script should not fail if user and group exists.

fixes #175

main/amavisd-new/APKBUILD

@@ -2,7 +2,7 @@
 # Maintainer: Leonardo Arena <rnalrd@gmail.com>
 pkgname=amavisd-new
 pkgver=2.6.4
-pkgrel=0
+pkgrel=1
 pkgdesc="High-performance interface between mailer (MTA) and content checkers"
 url="http://www.ijs.si/software/amavisd"
 license="GPL-2"

main/amavisd-new/amavisd-new.pre-install

@@ -1,4 +1,6 @@
 #!/bin/sh
 
-addgroup amavis
-adduser -D -S -G amavis -h /var/amavis -s /bin/false amavis
+addgroup amavis 2>/dev/null
+adduser -D -S -G amavis -h /var/amavis -s /bin/false amavis 2>/dev/null
+exit 0
+