https compatibility

I think the openwifimap should be https (only) ready.
Up to now all scrips and styles use http (hard coded).

A possible solution should be to use external sources without protocol `//something.com/file.css`

I tried it locally, but some of your sources don't use signed (only self signed) certificates. This will be blocked by the most browsers until the user accept the certificate manually.

Without this changes the openwifimap couldn't included in https pages like the [berlin freifunk](https://berlin.freifunk.net/network/map/) page or isn't displayed when using plugins like HTTPS Everywhere.

Inspect the HTML sources for hard-coded HTTP script and stylesheet URLs, then identify which external sources support HTTPS. Verify that the map can be embedded in an HTTPS page without mixed-content blocking, including the certificate caveat described in the issue.

Written by the indexing model from the issue text.