Fix a crash with protected Tor control port

[CyberTailor]

No description provided.

[CyberTailor]

Reference: #746

[MadcowOG]

This doesn't work, send_tor_signal is used for more than just to check for Tor availability. I made this same mistake in my pull request, too. We do need to authenticate with the Tor control port because of a new identity request.

This condition can be found at around line 300 in request.py:

# Validate Tor conn and request new identity if the last one failed
        if self.tor and not send_tor_signal(
                Signal.NEWNYM if attempt > 0 else Signal.HEARTBEAT):
            raise TorError(
                "Tor was previously enabled, but the connection has been "
                "dropped. Please check your Tor configuration and try again.",
                disable=True)

We use this to ask Tor for a new circuit in the case google starts rejecting our requests or hit us with a captcha.

[CyberTailor]

Oops, missed it. Now AuthentificationError sets TOR_AVAILABLE to 0.