Add missing deprecation notice

Author: picodexter

Console/Renderer/AbstractCryptRenderer.php

@@ -53,6 +53,9 @@ abstract public function getMessageForStaticKey();
      */
     public function renderOutput($result, TransformedKey $transformedKey, OutputInterface $output)
     {
+        /*
+         * @deprecated symfony/console 3.0 Use OutputInterface::isQuiet() instead
+         */
         if (OutputInterface::VERBOSITY_QUIET === $output->getVerbosity()) {
             $output->writeln($result, OutputInterface::VERBOSITY_QUIET);
         } else {