Conflict with vim-gitgutter signs

This plugin appears to take priority over [vim-gitgutter](https://github.com/airblade/vim-gitgutter) signs. It might have to do with the [sign id](https://github.com/maralla/validator.vim/blob/9f6ac58b2c69340d3f1d111d3b5199decd9cab60/autoload/validator/notifier.vim#L1).

EDIT: I'm not sure if this is possible, as I observed the same behavior in other plugins.