Bug#938960: apache2: systemd's apache2.service is silently overwritten on upgrades

[Emmanuel Bouaziz <ebouaziz@neotion.com>]

Source: apache2
Version: 2.4.25-3+deb9u8
Severity: normal

Dear Maintainer,

    I disabled systemd's privateTmp for Apache. Anytime the package is
    upgraded, privateTmp is enabled again.

    The affected file is /etc/systemd/system/multi-user.target.wants/apache2.service

    Expected behavior: on upgrades, merge config files or prompt about
    the maintainer file being different.

    This is apparently due to systemd's config files not being listed in
    the conffiles in the package's control info (whereas sysvinit's files
    are)


-- System Information:
Debian Release: 9.9
  APT prefers oldstable-updates
  APT policy: (500, 'oldstable-updates'), (500, 'oldstable')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 4.9.0-9-amd64 (SMP w/8 CPU cores)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_GB.UTF-8 (charmap=UTF-8) (ignored: LC_ALL set to en_US.UTF-8), LANGUAGE=en_US.UTF-8 (charmap=UTF-8) (ignored: LC_ALL set to en_US.UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)