Document mattermost using system’s SSL store instead of embedded.
Recently I've helped customers using GitLab with a self-signed cert that were surprised to find that they had to recognize the self-signed cert in the system's OpenSSL instead of the bundled one. I'm not sure if this is the desired behaviour, but we could make this clearer in our docs, especially since many users have a staging env with self-signed certs.
If this is not the desired behavior, should we loop in somebody from mattermost?
/cc @joshlambert