Unable to annotate L.A. Times (affects LMS users)

**Describe the bug**
An L.A. Times page isn't loading the sidebar in Via, and calls `via.hypothes.is///javascript:;` when loading.

**To Reproduce**
Steps to reproduce the behavior:
1. Go to https://via.hypothes.is/https://www.latimes.com/entertainment/tv/la-et-st-game-of-thrones-spin-off-competition-20190412-story.html
2. Open the Console, note errors
3. Open Network and refresh, note what fails to load.

**Expected behavior**
We would expect this site to mirror other news sites when loaded in Via. I.e., the site loads normally and the Sidebar appears.

**Screenshots**


**Desktop (please complete the following information):**
- OS: MacOS Mojave 10.14
- Chrome 83

**Additional context**
https://hypothesis.zendesk.com/agent/tickets/11015

Start by loading the Via URL for the L.A. Times article, then inspect the browser Console and Network panel as described. Compare the behavior with other news sites that load in Via; the work is done when the article loads normally and the Sidebar appears without the reported failures.

Written by the indexing model from the issue text.