fix "use of undeclared crate or module `mwtimestamp`" errors

I updated my dependencies and everything broke for me. The most outstanding one being "error[E0433]: failed to resolve: use of undeclared crate or module mwtimestamp".

This merge request should serve as a hotfix for that, I have tested that patch and confirms that my project compiles now. I have no time to file a Phabricator ticket.