FindMPI will now work when CUDA is disabled and CMake <= 3.11
requested to merge robertmaynard/vtk-m:find_mpi_work_with_older_cmake_version_when_cuda_disabled into master
This was causing issues for downstream users of VTK-m as it exposed a bug in CM ( cmake#17952 ) where it was evaluating against the set of enabled languages instead of possible languages.