Merge pull request #947 from echernyavskiy/patch-7

Fix PHP cheatsheets link (http -> https).

Author: Xymph

_posts/16-08-01-Sites.md

@@ -8,7 +8,7 @@ title:   Other Useful Resources
 
 ### Cheatsheets
 
-* [PHP Cheatsheets](http://phpcheatsheets.com/) - for variable comparisons, arithmetics and variable testing in various PHP versions.
+* [PHP Cheatsheets](https://phpcheatsheets.com/) - for variable comparisons, arithmetics and variable testing in various PHP versions.
 * [Modern PHP Cheatsheet](https://github.com/smknstd/modern-php-cheatsheet) - documents modern (PHP 7.0+) idioms in a unified document.
 * [OWASP Security Cheatsheets](https://owasp.org/www-project-cheat-sheets/) - provides a concise collection of high value information on specific application security topics.