Set Protobuf_FOUND to TRUE (#3840)
Set Protobuf_FOUND to TRUE (#3840)

This matches the behavior in FindProtobuf.cmake, https://github.com/Kitware/CMake/blob/master/Modules/FindProtobuf.cmake#L624-L626 (https://cmake.org/cmake/help/latest/module/FindPackageHandleStandardArgs.html#command:find_package_handle_standard_args)
NervanaSystems/ngraph,NervanaSystems/ngraph,NervanaSystems/ngraph,NervanaSystems/ngraph