Update Stoerungsampel HTTP Logging and HTTPS support

* plugin now logs errors to Error loglevel and successful posts to info
  loglevel.
* options for specification of ssl_version, ssl_verify_mode and
  ca_cert_file have been created
  when using plain http they should be ignored, nevertheless
  ca_cert_file has to be set in config.
  gematik also requires TLSv1.1 but currently the library cannot handle
  that. Support for TLS1.1 will be implemented at a future time.