Corrected NEKTAR_BUILD_TESTS condition
When the tutorial submodule is present in the development tree and NEKTAR_BUILD_TESTS is disabled, an error would be thrown. I believe this fixes it. Please double check my changes as I am no CMake expert.
When the tutorial submodule is present in the development tree and NEKTAR_BUILD_TESTS is disabled, an error would be thrown. I believe this fixes it. Please double check my changes as I am no CMake expert.