Make language defaults in line with old CMS values

This was always false in the CMS ever since the platform project. In the old framework project (https://github.com/joomla/joomla-framework/blob/staging/src/Joomla/Language/Text.php#L340) it was false, however from the first commit of the language package in this github repo it's been an array. I'm deprecating that functionality as it doesn't really seem to give you anything - the only 2 array params that do anything are the params of the function anyhow.

False is even the default value in the 2.x branch??