root condition does not work

[kyoh86]

Although condition returns false, winbar is there.
Sure, there's no contents in winbar, but the area is secured.

e.g.

setup({
    winbar = {
        condition = function()
            return false
        end
        provider = "foo"
    }
})

I expect it deletes winbar, but there's invisible winbar.

[kyoh86]

I could solved the issue.
We can use opts.disable_winbar_cg instead of the root condition.