Bug#283560: update-exim4.conf.8.gz: dc_smarthost can in fact be a list

[Dan Jacobson]

Package: exim4-config
Version: 4.34-6
Severity: minor
File: /usr/share/man/man8/update-exim4.conf.8.gz

Mention that
       dc_smarthost
              The host to which all outgoing mail is passed to and that  takes
              care  of  delivering  it.  Used  to  as value of the DCsmarthost
              macro.

can in fact be a list, e.g.,
dc_smarthost='fraudo.snoresh.net::587:porky.softstools.net'
of several machines and even ports to try, not just one, if in fact
this is the case.

Or emphasize that it can only be one (too bad).