[APPS-1392] Actually fix double count bug

:koala::+1:

/cc @zendesk/quokka @danielbreves @adammw 

### Description

Our nicer way didn't work because `this.ajax` returns promises instead of XHR objects, but this appears to do the job just as well.

### References
 - Jira link: https://zendesk.atlassian.net/browse/APPS-1392

### Risks
  - User data app breaks