Cannot load Youtube iframe

[fredele]

When navigating on Youtube, you can copy an integration code which resembles to this :

<iframe width="837" height="614" src="https://www.youtube.com/embed/XXXXXXXXX" title="title" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>

At the current state, the frame is displayed but not the video.
This behavior is due to the function "acceptNavigationRequest" in the file "webenginepreview.py"

If you add to this function this statement :

if url.scheme() == "https":
            return True

the iframe is properly loaded and the video displayed ...

( ...and yes, I know, I should do a proper pull request ...)

[mitya57]

Actually, I think we should fix this issue by allowing all requests when isMainFrame argument is False.