Also fix silent placeholder in new_reminder when reply has no content

Author: oliveman-au

bot/exts/utils/reminders.py

@@ -493,6 +493,8 @@ async def new_reminder(
         # If `content` isn't provided then we try to get message content of a replied message
         if not content:
             content = await self.try_get_content_from_reply(ctx)
+            if content is None:
+                return
 
         # Now we can attempt to actually set the reminder.
         reminder = await self.bot.api_client.post(