protobuf: remove gtest from runtime requires.
protobuf: remove gtest from runtime requires.

It's used only for tests.

Begasus/haikuports,haikuports/haikuports,Begasus/haikuports,haikuports/haikuports,Begasus/haikuports,haikuports/haikuports,haikuports/haikuports,haikuports/haikuports,Begasus/haikuports,Begasus/haikuports