WIP: Issue 7439 - Custom filter table: trigger an error on wrong header
This fixes https://gitlab.com/eyeo/adblockplus/abpui/adblockplusui/issues/392 for release-2019-1
branch.
This is just a reminder for the https://gitlab.com/eyeo/adblockplus/abpui/adblockplusui/merge_requests/257 since it needs more patches once 2018-5 will be merged.
Edited by Ursa Kacar