Default img url when adding media includes "http://etc" causing insecure content in https pages

[markcunningham]

New post, insert media, select an image and have a look at the <img src="" part. It links to the full "​http://website/wp-content" address causing images to be loaded as "insecure content" when the full page is loaded via ​https://website/

If this was instead just "/wp-content/bla", then when the page is loaded via https, all images would by default load with https as well, mitigating against insecure content loading.

[kurtpayne]

Related #17048

[solarissmoke]

There are several tickets related to http/https issues around images. This can probably be closed as a duplicate.

#13941, #15928, #19023, #18005, #19037

[bpetty]

Duplicate of #15928.