Sensor size is not imported

[Dene]

I've noticed that sensor size is not imported. And because of that actual focal length is imported incorrectly (based on default 36 mm sensor). Yes, it seems that field of view actually is the same (as in .fSpy) but toggle to millimeters and you'll notice the focal length what is different from the value in .fSpy

In Blender - sensor tweaking will change field of view as well, but doesn't change focal length in millimeters.

So the fix should be like that:

1. Set sensor size to blender camera first
2. Set field of view value

Thanks.