Prevented inadvertant logging during MFA flow

- Added StoppedAuthenticationException to dontReport list.
- Added test to cover.

Closes #3468

app/Exceptions/Handler.php

@@ -21,6 +21,7 @@ class Handler extends ExceptionHandler
      */
     protected $dontReport = [
         NotFoundException::class,
+        StoppedAuthenticationException::class,
     ];
 
     /**