Do not start bot with a message in chat.

fjerkroa_bot/discord_bot.py

@@ -59,7 +59,7 @@ class FjerkroaBot(commands.Bot):
     def init_boreness(self):
         if 'chat-channel' not in self.config:
             return
-        self.last_activity_time = 0.0
+        self.last_activity_time = time.monotonic()
         self.loop.create_task(self.on_boreness())
         logging.info('Boreness initialised.')