When running a `make manpages` the image `docker-manpage-dev` will be build and started to create
the man pages. But the container will not be deleted afterwards. So I propose to start it with
`docker run --rm ...`, otherwise we'll collect some trash.
```
$ docker ps -a
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
e3d9f721d862 docker-manpage-dev "man/generate.sh" 19 minutes ago Exited (0) 16 minutes ago berserk_jang
5738a23fb682 docker-manpage-dev "man/generate.sh" 9 hours ago Exited (0) 9 hours ago boring_bartik
15490b5e63f7 docker-manpage-dev "man/generate.sh" 10 hours ago Exited (0) 10 hours ago lonely_joliot
```
Signed-off-by: Dieter Reuter <dieter.reuter@me.com>
Upstream-commit: 12c10239bbff1def439193d4681464640446bfbb
Component: engine
c733ccf2f5