Update README.md

The Security Advistories Checker website will shut down at the end of October.

README.md

@@ -333,7 +333,7 @@ Please see [CONTRIBUTING](https://github.com/ziadoz/awesome-php/blob/master/CONT
 * [PHPSecLib](http://phpseclib.sourceforge.net/) - A pure PHP secure communications library.
 * [random_compat](https://github.com/paragonie/random_compat) - PHP 5.x support for `random_bytes()` and `random_int()`
 * [RandomLib](https://github.com/ircmaxell/RandomLib) - A library for generating random numbers and strings.
-* [SensioLabs Security Check](https://security.sensiolabs.org/) - A web tool to check your Composer dependencies for security advisories.
+* [Symfony Security Monitoring](https://security.symfony.com/) - A web tool to check your Composer dependencies for security advisories, previously known as "SensioLabs Security Check".
 * [TCrypto](https://github.com/timoh6/TCrypto) - A simple encrypted key-value storage library.
 * [VAddy](https://vaddy.net/) - A continuous security testing platform for web applications.
 * [Zed](https://www.owasp.org/index.php/OWASP_Zed_Attack_Proxy_Project) - An integrated penetration testing tool for web applications.