BUG/MINOR: proxy/cli: don't enumerate internal proxies on "show backend"

Commit e7f74623e ("MINOR: stats: don't output internal proxies (PR_CAP_INT)")
in 2.5 ensured we don't dump internal proxies on the stats page, but the
same is needed for "show backend", as since the addition of the HTTP client
it now appears there:

  $ socat /tmp/sock1 - <<< "show backend"
  # name
  <HTTPCLIENT>

This needs to be backported to 2.5.
1 file changed