systemd unit file in wrong location leads to problems after package updates #110
Description
Hi,
currently the role installs the systemd unit file in /lib/systemd/system, overwriting the existing file coming with the Debian package.
When updating Varnish, this file gets replaced by the package, resulting in potential startup errors because e.g. -p 'vcc_allow_inline_c=on' (via varnishd_extra_options) is no longer there. Varnish will then quit with VCL errors, when the VCL in place requires inline C support.
The correct place for the role-maintained systemd unit file would be /etc/systemd/system/varnish.service.
Validated only for Debian but should also be true for RedHat.