Missing check for config_dir on arm Macs

[tiiiecherle]

Describe the bug

Missing check for config_dir on arm Macs.

# Attempt to scan for a valid config dir
if [ -f "/etc/clamav-unofficial-sigs/master.conf" ] ; then
  config_dir="/etc/clamav-unofficial-sigs"
elif [ -f "/usr/local/etc/clamav-unofficial-sigs/master.conf" ] ; then
  config_dir="/usr/local/etc/clamav-unofficial-sigs/"
elif [ -f "/opt/zimbra/conf/clamav-unofficial-sigs/master.conf" ] ; then
  config_dir="/opt/zimbra/conf/clamav-unofficial-sigs/"
else
  xshok_pretty_echo_and_log "ERROR: config_dir (/etc/clamav-unofficial-sigs/master.conf) could not be found"
  exit 1
fi

The homebrew directory on arm Macs is

brew --prefix
/opt/homebrew

If I understand correctly there should be another check

elif [ -f "/opt/homebrew/etc/clamav-unofficial-sigs/master.conf" ] ; then
  config_dir="/opt/homebrew/etc/clamav-unofficial-sigs/"

How to reproduce the problem

running clamav-unofficial-sigs.sh on arm Mac results in

==============================================================================
ERROR: config_dir (/etc/clamav-unofficial-sigs/master.conf) could not be found
==============================================================================

Thanks for fixing in advance