[openrailwaymap] HTTPS support

Hello everybody,

today we enabled HTTPS on the server. Now you can access

* the website via https://www.openrailwaymap.org/, * tiles via https://tiles.openrailwaymap.org/, * the API via https://api.openrailwaymap.org/ and * the mailing list via https://lists.openrailwaymap.org/ .

Users who already embed our tiles or request our API in their HTTPS website will not get mixed content errors any more. And for users who have been prevented from using OpenRailwayMap content in their HTTPS- delivered website, there's no reason not to do so.

Best regards Alex