Don't try to remove players not in the player list

Fixes #47

minecraft_discord_bridge/minecraft_discord_bridge.py

@@ -717,6 +717,7 @@ class MinecraftDiscordBridge():
                 for webhook in self.webhooks:
                     requests.post(webhook, json=webhook_payload)
                 del self.uuid_cache[action.uuid]
+                if action.uuid in self.player_list:
                     del self.player_list[action.uuid]
                 if self.config.es_enabled:
                     self.es_logger.log_connection(