g:netrw_list_hide is partly cleared if != s:dotfiles

[fedorenchik]

If there is following line in .vimrc:
let g:netrw_list_hide = netrw_gitignore#Hide() . ',\(^\|\s\s\)\zs\.\S\+'
vim-vinegar will remove netrw_gitignore#Hide() or any other string.
Expected results:
vim-vinegar keep whole custom g:netrw_list_hide variable.