Force connection through Tor if 'Tor for all connections' enabled

I've noticed that if 'Tor for all connections' is enabled and Tor isn't working, ZeroNet automatically switches to standard (non Tor) connection. It may lead to deanonymisation of users: first user start posting content with identity X with Tor working, but then Tor malfunctions and ZeroNet switches to standard (non Tor) connection and user gets deanonymised. I think that if 'Tor for all connections' is enabled and Tor malfunctions ZeroNet should just prevent any connection to network to prevent deanonymisation.

No files or tests are named. Locate the connection handling for the “Tor for all connections” setting and the fallback to standard connections; done means that when Tor is unavailable, ZeroNet makes no network connection instead of switching to a non-Tor connection.

索引モデルが issue の本文から書いたものです。