Force HTTP links to HTTPS

[MV-GH]

Rewrites http links to https,

Android doesn't allow you to load HTTP due to clearText, so we rewrite them as HTTPS

Also fixes this annoying quirk in Linkify that creates HTTP links:

For instance, if you are matching web URLs you would supply the scheme http://. If the pattern matches example.com, which does not have a URL scheme prefix, the supplied scheme will be prepended to create http://example.com when the clickable URL link is created.

Fix #1192

[dessalines]

Nice, thx. That's unfortunate that android / markwon can't handle non-https images. I imagine every dev will have to implement this exact same workaround in some way. Thanks android.

[MV-GH]

It's pure, android limitation not related with markwon. IoS actually introduced this much earlier. And it's still possible to disable "cleartext" but not sure if this is wanted.