Algolia quota critically fails

[TomS-]

Describe the bug
Once the Algolia quota is hit, it critically fails completely shutting off the website.

production.ERROR: AlgoliaSearch\AlgoliaException: Operations quota exceeded, change plan to get more Operations. in /home/***/***.***.co.uk/statamic/vendor/algolia/algoliasearch-client-php/src/AlgoliaSearch/Client.php:992

To Reproduce
Steps to reproduce the behavior:
Since I've not actually used Algolia yet, I've just moved the website from local to my development server so I can get feedback. My steps are not actually because Algolia quota has been hit, but because the domain I used isn't in Algolias whitelist. The easiest way to reproduce is try updating the index from a domain that isn't trusted. However, this may still happen if Algolia hits it quota.

Expected behavior
It should fail silently, not updating the index.

Environment details (please complete the following information):

• Statamic Version 2.9.2
• Fresh Install or Upgrade:
• OS: Linux
• Browser: N/A
• Web Server: Apache
• PHP Version: 7.1
• Addons installed: Fetch