fix: gate RX_LOG channel decryption on rx_log_decrypt

[sg]

Problem

With [bot] rx_log_decrypt = false, RX_LOG channel-chat messages were still being decrypted — the firehose logged RX_LOG pl=GRP_TXT … text="…" with cleartext.

Cause

rx_log_decrypt correctly gates the bot's own RX_LOG ingest handler (_on_rx_log_data subscription), but run() called self.mc.set_decrypt_channel_logs(True) unconditionally. That turns on the meshcore library's channel-log decryption, which decodes RX_LOG channel messages and populates payload["message"] — and the always-on firehose (_record_packet) logs it.

Fix

Pass the flag through: set_decrypt_channel_logs(self.cfg.rx_log_decrypt). With rx_log_decrypt=false the library no longer decodes RX_LOG channel text → firehose is capture-only, matching the config's documented intent.

Notes (behavior that is not changed, and shouldn't be)

• Channel commands still work when rx_log_decrypt=false: those arrive via the radio's queued CHANNEL_MSG_RECV/get_msg path (the radio decrypts channels whose keys are programmed into it). rx_log_decrypt only governs the client-side RX_LOG path. To stop a channel being acted on, remove its key from the radio or restrict the command's allowed_channels.
• Repeat-tracking still decrypts the bot's own sent messages to detect rebroadcasts; that's gated by repeat_tracking, not rx_log_decrypt.

Testing

One-line library-call gate inside the connect path; not unit-testable without a live radio. Verified py_compile and that the call now passes self.cfg.rx_log_decrypt.