When "format_on_save" is enabled, first check if there are some error

As described somewhere else https://github.com/jdc0589/JsFormat/issues/112 Is problematic to auto-format automatically on save.

This requests avoids auto-format on save if there are some lint error. Currently it only checks for sublimelint not for errors reported by SublimeLinter3 which I do not use, and I don't know which regions adds. Would be easy to append to the list of regions if someone knows.