Hosted webrepl can't work due to HSTS

[ulope]

The server serving micropython.org is configured to send a HSTS header. This means all connections are forcibly upgraded to TLS (which in general is a good thing).

However the webrepl doesn't work over HTTPS (#15), therefore the hosted webrepl isn't usable for anyone.

Since the HSTS header doesn't set includeSubdomains it should be possible (depending on the hosting setup) to host the webrepl at e.g. webrepl.micropython.org without HTTPS.