Add access modifier to class constant

Signed-off-by: Matt Friedman <maf675@gmail.com>

Author: iMattPro

notification/method/webpush.php

@@ -52,7 +52,7 @@ class webpush extends messenger_base implements extended_method_interface
 	protected $push_subscriptions_table;
 
 	/** @var int Fallback size for padding if endpoint is mozilla, see https://github.com/web-push-libs/web-push-php/issues/108#issuecomment-2133477054 */
-	const MOZILLA_FALLBACK_PADDING = 2820;
+	public const MOZILLA_FALLBACK_PADDING = 2820;
 
 	/**
 	 * Notification Method Web Push constructor