Better handling of images not served over HTTPS

[azw413]

I've tried a few SBS 3D images and I always get the same result: views fine in non-VR mode but the 'Enter VR' mode doesn't seem to enter the WebXR mode and instead just displays a binocular stereo view with image data only in the left eye, which does respond to headset movement but the right eye is empty and it just doesn't enter the WebXR view so there's no 3D visualisation. Here's two examples, one a VR180 fisheye SBS image from a Insta360 Evo and a non VR-180 3d image from a Sony Bloggie 3d camera. Example code :-

<stereo-img src="media/bloggie.jpg" wiggle="false"></stereo-img>