allow null files when using {read: false} since file contents are irrelevant

[pgilad]

This will speed up builds, since the only relevant info you need from file is file.path

edit probably only useful if you use {timestamp: true, hash: false}
If you use hash option that it's irrelevant

[gronke]

@pgilad Not sure what the change is. Can you be a little bit more specific what has to be changed to adopt your recommendation? A Pull-Request would be super nice. 😜