dist/redhat/scylla-server.spec: Limit ninja-build jobs
dist/redhat/scylla-server.spec: Limit ninja-build jobs

Our C++ compilation takes up so much memory that we cannot really use
RPM defaults. Limit the number of jobs to 2 for now to fix SIGBUS errors
in VMs as well as swap storm when building with mock.

Signed-off-by: Pekka Enberg <add4fcd06328a394f0ad91feda7ee057316dc5ed@cloudius-systems.com>

dwdm/scylla,phonkee/scylla,tempbottle/scylla,stamhe/scylla,glommer/scylla,rluta/scylla,rentongzhang/scylla,guiquanz/scylla,capturePointer/scylla,wildinto/scylla,justintung/scylla,victorbriz/scylla,linearregression/scylla,duarten/scylla,tempbottle/scylla,asias/scylla,capturePointer/scylla,senseb/scylla,respu/scylla,phonkee/scylla,bowlofstew/scylla,gwicke/scylla,dwdm/scylla,acbellini/scylla,acbellini/scylla,justintung/scylla,guiquanz/scylla,capturePointer/scylla,linearregression/scylla,tempbottle/scylla,justintung/scylla,asias/scylla,guiquanz/scylla,glommer/scylla,dwdm/scylla,gwicke/scylla,victorbriz/scylla,victorbriz/scylla,aruanruan/scylla,wildinto/scylla,kangkot/scylla,scylladb/scylla,linearregression/scylla,gwicke/scylla,avikivity/scylla,rentongzhang/scylla,raphaelsc/scylla,aruanruan/scylla,kjniemi/scylla,aruanruan/scylla,rentongzhang/scylla,kangkot/scylla,scylladb/scylla,shaunstanislaus/scylla,duarten/scylla,stamhe/scylla,phonkee/scylla,kjniemi/scylla,respu/scylla,eklitzke/scylla,kjniemi/scylla,asias/scylla,bowlofstew/scylla,avikivity/scylla,duarten/scylla,avikivity/scylla,kangkot/scylla,stamhe/scylla,raphaelsc/scylla,rluta/scylla,scylladb/scylla,eklitzke/scylla,shaunstanislaus/scylla,senseb/scylla,raphaelsc/scylla,scylladb/scylla,respu/scylla,acbellini/scylla,glommer/scylla,wildinto/scylla,rluta/scylla,shaunstanislaus/scylla,senseb/scylla,eklitzke/scylla,bowlofstew/scylla