Revert re-enabling mpi-hs, #4068
Revert re-enabling mpi-hs, #4068

iand675/stackage,soenkehahn/stackage,int-index/stackage,jonschoning/stackage,spencerjanssen/stackage,fimad/stackage,asr/stackage,mrkkrp/stackage,michalkonecny/stackage,ethercrow/stackage,Daniel-Diaz/stackage,athanclark/stackage,clinty/stackage,simonmichael/stackage,wereHamster/stackage,massysett/stackage,stackbuilders/stackage,mstksg/stackage,fpco/stackage,peti/stackage