Remove additional flag for Visual

[senhuang42]

Now that ZSTD_DISABLE_DEPRECATE_WARNINGS is in the source code itself, including them in vcxproj files will cause a C4005 macro redefinition warning. So we should remove them to avoid appveyor failures.

Test Plan:

• Appveyor

[senhuang42]

Hmm, appveyor has been queued for over an hour, not sure how to force it to run.

[Cyan4973]

We do have a time-length pb with Appveyor tests.
When one specific test should be run swiftly, best way is to cancel all prior runs queued before.

[senhuang42]

We do have a time-length pb with Appveyor tests.
When one specific test should be run swiftly, best way is to cancel all prior runs queued before.

Ah, it seems like I don't have permissions to cancel any appveyor runs, but the ones on just PRs seem to be a little faster.

[Cyan4973]

Appveyor tests moved towards d3634bf