XDCR should return correct http response for cbauth authentication error

With MB-41733, an authentication error should result in a valid response back to the UI... instead, XDCR's response causes an odd error to be displayed

The issue is that XDCR is returning an array back instead of a map, with errors. Perhaps due to the new angular? UI has issues parsing the array to the screen. Changing it to an error map will cause it to display it correctly.

Before using map:

After using map: