Do not compile NetCDF tests when we do not have NetCDF
Do not compile NetCDF tests when we do not have NetCDF

chemfiles/chemfiles,lscalfi/chemfiles,lscalfi/chemfiles,Luthaf/Chemharp,chemfiles/chemfiles,lscalfi/chemfiles,lscalfi/chemfiles,chemfiles/chemfiles,chemfiles/chemfiles,Luthaf/Chemharp,Luthaf/Chemharp