Bug#1024592: systemd configuration for inetd mode is broken in 1:9.1p1-1

Package: openssh-server
Version: 1:9.1p1-1
Severity: minor

 After upgrade from 1:9.0p1-1+b1 to 1:9.1p1-1 sshd starts under systemd
 as standalone daemon only.

 1. File /lib/systemd/system/[email protected] is missing in 1:9.1p1-1,
    while /lib/systemd/system/ssh.socket is present.
    So sshd can not be run as inetd-style service, because ".socket"
    requires apropriate "@.service" unit.

 2. Unit file /lib/systemd/system/ssh.socket has considerable changes
    in comparison with old 1:9.0p1-1+b1. First, it's [Unit] section
    has "Before=sockets.target", and [Install] section has
    "WantedBy=sockets.target", it seems contradictionry to me.
    Then, old version 1:9.0p1-1+b1 has two options in this section:
    "Before=ssh.service" and "Conflicts=ssh.service". It prevents
    from concurent access to listening socket. New package 1:9.1p1-1
    has no such options.

 Result: with ssh.service=disabled and ssh.socket=enabled port 22 is
 listened by two process: by systemd and by sshd daemon. All incoming
 connections are handled by standalone sshd daemon, probably because
 systemd can't handle them due to absence of @.service unit file.

 If unit files ssh.socket and [email protected] are taken from old package,
 all works right as expected.