The lists do not update when there are no warnings/errors

[piotr-machura]

As stated in the title, these lines in loclist.lua

  if warnings + errors > 0 then

and quickfix.lua

  if #all_diagnostics > 0 then

prevent the lists from updating when there are no errors/warnings left.
Screenshot:

Then I comment the incorrect line and the windows closes, but another :copen shows the errors still there:

Edit: I have created a PR with a possible simple solution. Let me know what you think.