If an SSL error would occur then Armadillo Client should provide more informational error message

[christianhilbrands]

Issue:

When you try to get a token from armadillo in R you get an error that say's:
Error in curl:curl_fetch_memory(url, handle = handle) :
SSL certificate problem: unable to get local issuer certificate

Cause:

The cause is that armadillo server uses three different certificates for three different applications that need to talk to each other. Because it is not known which certificate gives the difficulties, it is not clear what certificate gives the issues. When you use let's encrypt, every part of the certificate(certificate, fullchain, private key) are stored in a different file.

(Proposed) solution:

If an SSL error would occur, let RStudio/RServer print the domain(armadillo.{domain}, armadillo-auth.{domain}...) in audition of the SSL error.
Example:
Error in curl:curl_fetch_memory(url, handle = handle) :
SSL certificate problem: unable to get local issuer certificate from {domain}