Update protobuf module to get fix for CMake 3.0

Update to a version of protobuf that does not try to use the LOCATION
target property deprecated by CMake 3.0 policy CMP0026.

Change-Id: Ic30dec8a5fc9f4c9bfcf6c4e2416f9e356c2dd8b
Merge topic 'update-protobuf' into next

b1c92065 Update protobuf module to get fix for CMake 3.0