Adding ARG and ENV directives allows users to explicitly set the tap interface at build time with `--buildargs` or at run time with `--env`. This is useful for hosts with multiple network interfaces, or when the tap interface isn't the second interface listed by `/sbin/ip address`.
fix condition when no internet connection is available
check internet connection before download of rules and avoid errors
check internet connection before setting up capture filters (with FQDNs, resulted in endless restart of suricata) and unset capture filters if no internet connection is available