text.js plugin module config "useXhr" option is broken

This feature worked with 2.1.5 which I confirmed with this test case.

I can make a change in the plugin to make it work, but considering it worked with requirejs 2.1.5 I think a bigger problem may have been introduced in require.js.

I believe this commit probably broke it https://github.com/jrburke/requirejs/commit/89ce62b725a7f7415dcae748e883d958da83e5f0 .