Check for an existing webhook made by the bot first.

Otherwise, it'd create a new one and in case of failures or database corruptions,
you'd hit the webhook limit quickly.

This was a feature pre-rewrite but got lost in translation.

src/pluralkit/bot/__init__.py

@@ -79,7 +79,7 @@ def run():
                 return
 
             # Second pass: do proxy matching
-            await proxy.try_proxy_message(conn, message, logger)
+            await proxy.try_proxy_message(conn, message, logger, client.user)
 
     @client.event
     async def on_raw_message_delete(payload: discord.RawMessageDeleteEvent):
@@ -127,6 +127,9 @@ def run():
             traceback_str = "```python\n...{}```".format(traceback.format_exc()[- (2000 - len("```python\n...```")):])
         await log_channel.send(content=traceback_str, embed=embed)
 
+        # Print it to stderr anyway, though
+        logging.getLogger("pluralkit").exception("Exception while handling event {}".format(event_name))
+
     bot_token = os.environ["TOKEN"]
     if not bot_token:
         print("No token specified. Please pass a valid Discord bot token in the TOKEN environment variable.",