Document an example wait timeout for MySQL in case the web hoster is killing...

Document an example wait timeout for MySQL in case the web hoster is killing the connection too early - fixes #15407

This reverts commit e9a9af34.

config/config.sample.php

@@ -1010,10 +1010,11 @@ $CONFIG = array(
 
 /**
  * Additional driver options for the database connection, eg. to enable SSL
- * encryption in MySQL.
+ * encryption in MySQL or specify a custom wait timeout on a cheap hoster.
  */
 'dbdriveroptions' => array(
 	PDO::MYSQL_ATTR_SSL_CA => '/file/path/to/ca_cert.pem',
+	PDO::MYSQL_ATTR_INIT_COMMAND => 'SET wait_timeout = 28800'
 ),
 
 /**