FindMPI: Fix regression in pthread guard
Fix a regression from !4970 (merged) with MPI and CUDA<10.2 that did let -pthread
flags slip to nvcc
again.
Affected releases: CMake 3.18.0-rc4 til 3.18.1
Fixes: #21108 (closed)
Backport: release
Topic-rename: FindMPI-cuda-pthread
Edited by Brad King