docuchat v0.3.1 — Security patch (Gmail TLS)

docuchat v0.3.1 — Security patch

Recommended update for anyone who connected, or plans to connect, the Gmail
import. Everything in v0.3.0 (28 live connectors, one-click updates, faster
first answers) is included.

Fixed: Gmail import now verifies the server certificate

The Gmail connector opened its IMAP connection without validating the server's
TLS certificate. The connection was encrypted, but on a hostile network an
attacker impersonating imap.gmail.com could have captured the Google app
password and read imported mail. The connection now verifies the certificate
and hostname before any credential is sent. No other connector was affected.

Also hardened

• Nextcloud connections are forced to HTTPS so the app password can never be
  sent over plain http.
• Imported-file names are fully sanitized before touching disk.