Add timeout parameter for database connection

config.default.php

@@ -88,6 +88,9 @@ define('DB_SSL_CA', null);
 // Mysql SSL server verification, set to false if you don't want the Mysql driver to validate the certificate CN
 define('DB_VERIFY_SERVER_CERT', null);
 
+// Timeout value for PDO attribute
+define('DB_TIMEOUT', null);
+
 // Enable LDAP authentication (false by default)
 define('LDAP_AUTH', false);