Twitter API is now HTTPS only. Ensure tmhOAuth can find the CA-file.

Twitter now only allows HTTPS-API-Requests (see https://dev.twitter.com/discussions/24239). Commit just changes URL. Note that tmhOAuth may need an additional CA-File for SSL (see https://github.com/themattharris/tmhOAuth#a-note-about-security-and-ssl)