testing/usbmuxd: fix post-install exit code

otherwise it exits with 1 when user exists

testing/usbmuxd/APKBUILD

@@ -2,7 +2,7 @@
 maintainer="Krassy Boykinov <kboykinov@teamcentrixx.com>"
 pkgname=usbmuxd
 pkgver=1.1.1
-pkgrel=7
+pkgrel=8
 pkgdesc="Socket Daemon to multiplex connections from iOS"
 url="https://libimobiledevice.org"
 arch="all"

testing/usbmuxd/usbmuxd.post-install

@@ -2,3 +2,5 @@
 
 # creating default user required by usbmuxd
 adduser -S -G dialout -H -g "usbmux daemon" usbmux 2>/dev/null
+
+exit 0