message: Fix CMake for adding GTest/
diff: -set(KWSYS_NAMESPACE adios2sys)
  -set(KWSYS_USE_DynamicLoader ON)
  -set(KWSYS_BUILD_SHARED OFF)
  -if(NOT ADIOS_BUILD_SHARED_LIBS)
  - set(KWSYS_INSTALL_EXPORT_NAME adios2)
  - set(KWSYS_INSTALL_LIB_DIR ${CMAKE_INSTALL_LIBDIR})
  -endif()
  +set(BUILD_GTEST ON)
  +set(BUILD_GMOCK OFF)
  -add_subdirectory(adios2sys)
  -
  -# Add the include usage requirements for KWSys
  -target_include_directories(adios2sys
  - INTERFACE ${CMAKE_CURRENT_BINARY_DIR}/adios2sys
  -)
  +add_subdirectory(googletest)
  