due to the usage of httplib.HTTPConnection the metrics collections fails silently if an https url is provided, which causes quite some debugging effort. The error logging needs to be improved for this case and SSL support could be added by using httplib.HTTPSConnection.
I was about to send a PR to support https but I consider my quick fix not very secure as it trusts any certificates, which should be at least configurable. If anyone really requires this, I can give it a shot once I free up some time (sorry), or someone else tackles this.