Changing image and URL references to https

[f27wood]

Currently the API is https, however some of the metadata referneces http URLs.

In order to make our new website https compliant including mixed content, the links to http://collectionsearch.nma.gov.au/ need to be updated to https.

In order to do this, the Museum first needs to make these URLs https.

BTW this is not needed prior to our new website going live on 18 October as previously thought, but hopefully asap afterwards (it will depend on how quickly wee can change collectionsearch.nma.gov.au to be https.).

[Conal-Tuohy]

For reference, the HTTP scheme used in those URLs is specified in these two parts of the ETL code:

• https://github.com/NationalMuseumAustralia/Collection-API-ETL/blob/master/piction-to-rdf.xsl#L76
• https://github.com/NationalMuseumAustralia/Collection-API-ETL/blob/master/emu-to-crm.xsl#L36

As soon as the images are actually available via HTTPS, it will be enough to change those two values above, and then run a full ETL.