Altered Samples/testStdConnection.php

This sample was no longer correct, as recent versions of iSDK accept Application Name and API Key as parameters of iSDK::cfgCon; iSDK::stdCon was removed in https://github.com/infusionsoft/PHP-iSDK/commit/26aa2d5fb75084ef46b046aafa9e4cd9cfa2ba9e#src