chore: fix link in readme (GoogleCloudPlatform#1388)

Author: bshaffer

appengine/wordpress/README.md

@@ -6,5 +6,5 @@ This is a list of samples which contain a CLI tool for deploying WordPress to Ap
 
 |Runtime|Description|
 |---|---|
-|[App Engine Standard for PHP 7.2](../php72/wordpress) (**Recommended!**)|The latest App Engine Runtime, and the latest version of PHP!|
+|[App Engine Standard](../standard/wordpress) (**Recommended!**)|The latest App Engine Runtime, and the latest version of PHP!|
 |[App Engine Flexible Environment](../flexible/wordpress)|Longer deployments, but allows for custom containers using Docker. Use this only if you're certain you need these features.|