Synchronous XMLHttpRequest warning when Access Alert is dismissed

[rpokorny]

Steps to reproduce:

1. Make sure that your browser dev tools are open to the Console tab
2. Log into an instance of OWF that has the Access Alert enabled.
3. Click the OK button on the Access Alert

Expected Results: the Access Alert is dismissed and the rest of the app loads. No errors in the dev console
Actual Results: Everything loads as it should but the following warning appears in the dev console:

"Synchronous XMLHttpRequest on the main thread is deprecated because of its detrimental effects to the end user's experience. For more help, check https://xhr.spec.whatwg.org/."

[rpokorny]

Fix committed; pending testing

[mparizernc]

Verified in Chrome, FF and IE the console error no longer appears.