Blocking remote fonts breaks gitlab

[l29ah]

Prerequisites

• [x] I verified that this is not a filter issue
  • Filter issues MUST be reported at filter issue tracker
• [x] This is not a support issue or a question
  • Support issues and questions are handled at /r/uBlockOrigin
• [x] I performed a cursory search of the issue tracker to avoid opening a duplicate issue
  • Your issue may already be reported.
• I tried to reproduce the issue when...
  • [ ] uBlock Origin is the only extension
  • [ ] uBlock Origin with default lists/settings
  • [ ] using a new, unmodified browser profile
• [x] I am running the latest version of uBlock Origin
• [x] I checked the documentation to understand that the issue I report is not a normal behavior

Description

When remote fonts are forbidden in ublock, then the tabs on that page don't show any content.

A specific URL where the issue occurs

https://gitlab.com/pkill-9

Steps to Reproduce

Open the link and poke around the tabs.

Expected behavior:

Content.

Actual behavior:

No content.

Your environment

• uBlock Origin version: v1.16.4.29
• Browser Name and version: palemoon 29.2.1
• Operating System and version: Gentoo GNU/Linux

[JustOff]

This is not a uBlock Origin issue, see https://github.com/JustOff/github-wc-polyfill/issues/26.