suppress CUDA check on OSX if CUDA cannot be uninstalled. fixes #663
suppress CUDA check on OSX if CUDA cannot be uninstalled. fixes #663

CompEvol/beast2,tgvaughan/beast2,Anaphory/beast2,tgvaughan/beast2,CompEvol/beast2,Anaphory/beast2,Anaphory/beast2,CompEvol/beast2,Anaphory/beast2,tgvaughan/beast2,tgvaughan/beast2,CompEvol/beast2