Highlighting does not work if markers are not visible

[uloco]

When the conflict is very big and I scroll out of the conflict markers, git-conflict stops highlighting those areas.
It should still highlight areas even when conflict markers are not visible but present in the file.

[akinsho]

@uloco I believe this is an upstream neovim issue but cannot find a reference. I observe the same behaviour with other plugins

[chase]

I can confirm that it behaves as expected in nvim v0.10