Merge pull request #9275 from alalek:cmake_protobuf_optional
authorAlexander Alekhin <alexander.a.alekhin@gmail.com>
Mon, 31 Jul 2017 12:03:54 +0000 (12:03 +0000)
committerAlexander Alekhin <alexander.a.alekhin@gmail.com>
Mon, 31 Jul 2017 12:03:54 +0000 (12:03 +0000)

Trivial merge