Tumblr scraper not working

[TheSmilingPony]

Describe the bug
Attempting to use a Tumblr image post as a source to Fetch will not load anything. Example: https://the-smiling-pony.tumblr.com/post/634066037897314304

Note that this could be a bit egregious as the placeholder text in the field explicitly mentions Tumblr

To Reproduce
Steps to reproduce the behavior:

1. Go to New
2. Paste a Tumblr image post into the Fetch field
3. Click on Fetch
4. Observe nothing is loaded

Expected behavior
Tumblr image posts and (text posts) can be fetched

Additional context
Note that this currently appears to work on Derpibooru