hotfix, ensure null for image unused urls

src/discord/message.py

@@ -24,7 +24,7 @@
 class DiscordMessage:
 	"""A class defining a typical Discord JSON representation of webhook payload."""
 	def __init__(self, message_type: str, event_type: str, webhook_url: str, content=None):
-		self.webhook_object = dict(allowed_mentions={"parse": []}, avatar_url=settings["avatars"].get(message_type, ""))
+		self.webhook_object = dict(allowed_mentions={"parse": []}, avatar_url=settings["avatars"].get(message_type, None) or None)
 		self.webhook_url = webhook_url
 
 		if message_type == "embed":
@@ -77,8 +77,10 @@ def finish_embed(self):
 			self.embed["author"]["icon_url"] = settings["event_appearance"][self.event_type]["icon"]
 		if len(self.embed["title"]) > 254:
 			self.embed["title"] = self.embed["title"][0:253] + "…"
+		if not self.embed["author"].get("icon_url", None) and self.embed["author"].get("icon_url", None) is not None:
+			self.embed["author"]["icon_url"] = None
 
-	def set_author(self, name, url, icon_url=""):
+	def set_author(self, name, url, icon_url=None):
 		self.embed["author"]["name"] = name
 		self.embed["author"]["url"] = url
 		self.embed["author"]["icon_url"] = icon_url
@@ -89,7 +91,7 @@ def add_field(self, name, value, inline=False):
 		self.embed["fields"].append(dict(name=name, value=value, inline=inline))
 
 	def set_avatar(self, url):
-		self.webhook_object["avatar_url"] = url
+		self.webhook_object["avatar_url"] = url or None
 
 	def set_name(self, name):
 		self.webhook_object["username"] = name