Custom filter table: Disabled filter is re-enabled after refresh in the UI

Issue

In current release 2018-5 if the custom filter is disabled (via the toggle), it will be re-enabled after the page is refreshed.

Reproduced in latest versions of Chrome, Opera and Firefox (did not try older browser versions)

Reproduction steps

1. Open the Options page and navigate to the Custom Filters Table in the Advanced tab
2. Add a custom filter
3. Disable the custom filter
4. Refresh the page

--> notice that disabled filter has been re-enabled.

Expand for .gif of the issue

Expected behavior

Disabled custom filter should remain disabled after the Options page is refreshed.

Hints for testers

This is the same underlying issue as #420 (closed). Therefore we should also verify that the change for this issue also fixes the problem described in #420 (closed) and, if it doesn't, reopen it.