title: "Protobuf compiler version doesn't match library version 3.6.1" when not using system Protobuf library
body: <p>I am using CMake as a build tool and have pre-packaged binaries for all libraries I use in my project. One of those libraries is Protobuf and gets downloaded via Conan IO. So, I want to use the Protobuf downloaded by Conan and not the one already installed by Linux. The problem is that I get the following error when running <code>CMake</code>:</p>
  
  <pre><code>CMake Warning at /home/username/Documents/project/test/build/venv/lib/python3.6/site-packages/cmake/data/share/cmake-3.10/Modules/FindProtobuf.cmake:455 (message):
    Protobuf compiler version doesn't match library version 3.6.1
  Call Stack (most recent call first):
    /home/username/Documents/project/test/script/cmake/Env.cmake:139 (include)
    CMakeLists.txt:6 (include)
  
  
  -- Found Protobuf: /home/username/Documents/project/test/build/venv/.conan/data/Protobuf/3.6.1/project/dev/package/80043e232e8ab07f4b25e67652a9490d9ad33d91/lib/libprotobuf.so;-lpthread (found version "3.6.1") 
  CMake Warning at /home/username/Documents/project/test/build/venv/lib/python3.6/site-packages/cmake/data/share/cmake-3.10/Modules/FindProtobuf.cmake:455 (message):
    Protobuf compiler version doesn't match library version 3.6.1
  Call Stack (most recent call first):
    /home/username/Documents/project/test/src/shared/bysp/CMakeLists.txt:9 (find_package)
  </code></pre>
  
  <p>Is there a way to fix this? Is this something that can cause errors? </p>