In https://sourceforge.net/p/roundup/mailman/message/37680982/
with subject "Starting tracker gives [('SSL routines', '', 'PEM lib')]"

it looks like the format of the PEM file to give to roundup-server when operating in
SSL/TLS mode isn't properly described.

The file needs to have both the key surrounded by private key markers
something like:

----- BEGIN PRIVATE KEY ----
----- END PRIVATE KEY   ----

and the corresponding certificate (in PKCS#8 format)
surrounded by the certificate markers like:

---- BEGIN CERTIFICATE ----

and similar for end. This can be done by concatenating the key and certificate
files together into one file and using that file.

Add doc on this in a couple of places:

  to the config in roundup-server so it is added to the generated config file

  in the roundup-server man page

Also that error is a bit cryptic. Consider trapping it and the error shown in:

   https://sourceforge.net/p/roundup/mailman/message/37681042/

when the PEM file only has the key in it and producing a more useful error.
Maybe:

 PEM file seems to have an error does it contain both a key and certificate?

Note until issue 2551137 is solved, this is a bit of a moot point as roundup-server won't
serve anything, but having it fixed is still a win.