docs: Update webhook struct docs to indicate exclusivity

Author: Enovale

include/dpp/webhook.h

@@ -114,13 +114,15 @@ class DPP_EXPORT webhook : public managed, public json_interface<webhook> {
 	/**
 	 * @brief The default avatar of the webhook.
 	 *
+	 * @note This value will not have any effect when `avatar_url` is set, they are mutually exclusive.
 	 * @note This may be empty.
 	 */
 	utility::iconhash avatar;
 
 	/**
 	 * @brief Avatar URL to use instead of the default if it is set.
 	 *
+	 * @note This will override `avatar` if it is set, they are mutually exclusive.
 	 * @note This may be empty.
 	 */
 	std::string avatar_url;

src/dpp/cluster/webhook.cpp

@@ -73,7 +73,7 @@ void cluster::execute_webhook(const class webhook &wh, const struct message& m,
 		{"with_components", true},
 	});
 	std::string body;
-	if (!thread_name.empty() || !wh.avatar.to_string().empty() || !wh.avatar_url.empty() || !wh.name.empty()) { // only use json::parse if thread_name is set
+	if (!thread_name.empty() || !wh.avatar.to_string().empty() || !wh.avatar_url.empty() || !wh.name.empty()) { // only use json::parse if a value needs to be changed
 		json j = m.to_json(false);
 		if (!thread_name.empty()) {
 			j["thread_name"] = thread_name;