Update make_for_win.bat

- Revert version to what is currently in develop branch to clarify what changed.

protobuf-definitions/make_for_win.bat

 rem GRPC-TOOLS required. Install with `nuget install Grpc.Tools`. 
 rem Then un-comment and replace [DIRECTORY] with location of files.
 rem For example, on Windows, you might have something like:
-rem set COMPILER=Grpc.Tools.1.11.0\tools\windows_x64
+rem set COMPILER=Grpc.Tools.1.14.1\tools\windows_x64
 
 set SRC_DIR=proto\mlagents\envs\communicator_objects
 set DST_DIR_C=..\UnitySDK\Assets\ML-Agents\Scripts\CommunicatorObjects