Fetch protobuf (#4837)
Fetch protobuf (#4837)

* Try to simplifiy Protobuf logic.

* Try updating WIN32 build.

* Fix macos build issue.

* Cleanup unused arg.

Co-authored-by: Robert Kimball <f8f4fb0160c4e961c3d6afdbdcc40cfc21344ca8@intel.com>
NervanaSystems/ngraph,NervanaSystems/ngraph,NervanaSystems/ngraph,NervanaSystems/ngraph