Rework protobuf dependency to use import library

#233

Author: SamVanheer

src/CMakeLists.txt

@@ -170,16 +170,8 @@ protobuf_generate_cpp(GNS_COMMON_PROTO_SRCS GNS_COMMON_PROTO_HDRS ${GNS_COMMON_P
 protobuf_generate_cpp(GNS_CLIENTLIB_PROTO_SRCS GNS_CLIENTLIB_PROTO_HDRS ${GNS_CLIENTLIB_PROTOS})
 
 function(gns_set_target_protobuf_properties TGT )
-	target_include_directories(${TGT} PRIVATE
-
-		# Only necessary if we're not using protobuf::libprotobuf
-		# But that's not supported until CMake 3.9
-		${Protobuf_INCLUDE_DIRS}
-		)
-
 	target_link_libraries(${TGT} PUBLIC
-		# protobuf::libprotobuf
-		${PROTOBUF_LIBRARIES}
+		protobuf::libprotobuf
 		Threads::Threads
 		)
 endfunction()