Revert "Use an array for the avatar string"

This reverts commit 017d517.

notification/method/webpush.php

@@ -445,7 +445,7 @@ protected function clean_expired_subscriptions(array $user_subscription_map, arr
 	 * into https://myboard.url/path/to/avatar=123456789.gif
 	 *
 	 * @param string $avatar
-	 * @return array Absolute path to avatar image in an array with src as its key
+	 * @return string Absolute path to avatar image
 	 */
 	protected function prepare_avatar($avatar)
 	{
@@ -455,7 +455,7 @@ protected function prepare_avatar($avatar)
 
 		$path = !empty($matches[1]) ? end($matches[1]) : $avatar;
 
-		return ['src' => preg_replace('#^' . preg_quote($this->path_helper->get_web_root_path(), '#') . '#', $this->get_board_url(), $path, 1)];
+		return preg_replace('#^' . preg_quote($this->path_helper->get_web_root_path(), '#') . '#', $this->get_board_url(), $path, 1);
 	}
 
 	/**

styles/all/template/push_worker.js.twig

@@ -36,7 +36,7 @@ self.addEventListener('push', event => {
 			const options = {
 				body: responseBody,
 				data: response,
-				icon: response.avatar.src,
+				icon: response.avatar,
 			};
 			self.registration.showNotification(response.heading, options);
 		});