p4vfs doesn't respect the servers +m flag

[MGJim]

p4vfs always uses the current time as timestamp when syncing files even if the server has +m modifier associated with the file.
This breaks all tooling relying on modtime.

[jessk-msft]

Hi Jim,
Yes this certainly looks like the case. We haven't given proper attention to the preservation of file modtime when doing a virtual sync. Thanks for bringing this to our attention. This is definitely worth fixing.

-Jess