qemu: Use correct default model on s390
qemu: Use correct default model on s390

Commit a68d6726679323823ee5be47f0144e9ccffa0757 breaks networking on s390 as it
changes the default network card model.

taget/libvirt,shugaoye/libvirt,datto/libvirt,nertpinx/libvirt,nertpinx/libvirt,agx/libvirt,jfehlig/libvirt,olafhering/libvirt,taget/libvirt,andreabolognani/libvirt,agx/libvirt,libvirt/libvirt,rlaager/libvirt,eskultety/libvirt,olafhering/libvirt,crobinso/libvirt,VenkatDatta/libvirt,eskultety/libvirt,jfehlig/libvirt,nertpinx/libvirt,agx/libvirt,zippy2/libvirt,taget/libvirt,zhlcindy/libvirt-1.1.4-maintain,cbosdo/libvirt,crobinso/libvirt,eskultety/libvirt,andreabolognani/libvirt,zhlcindy/libvirt-1.1.4-maintain,andreabolognani/libvirt,jfehlig/libvirt,elmarco/libvirt,shugaoye/libvirt,datto/libvirt,fabianfreyer/libvirt,cbosdo/libvirt,fabianfreyer/libvirt,jardasgit/libvirt,cbosdo/libvirt,shugaoye/libvirt,elmarco/libvirt,zippy2/libvirt,jardasgit/libvirt,VenkatDatta/libvirt,libvirt/libvirt,agx/libvirt,fabianfreyer/libvirt,nertpinx/libvirt,fabianfreyer/libvirt,agx/libvirt,VenkatDatta/libvirt,VenkatDatta/libvirt,elmarco/libvirt,shugaoye/libvirt,zhlcindy/libvirt-1.1.4-maintain,nertpinx/libvirt,rlaager/libvirt,elmarco/libvirt,rlaager/libvirt,olafhering/libvirt,zippy2/libvirt,jfehlig/libvirt,libvirt/libvirt,shugaoye/libvirt,rlaager/libvirt,zhlcindy/libvirt-1.1.4-maintain,cbosdo/libvirt,zippy2/libvirt,eskultety/libvirt,andreabolognani/libvirt,olafhering/libvirt,libvirt/libvirt,rlaager/libvirt,datto/libvirt,jardasgit/libvirt,fabianfreyer/libvirt,VenkatDatta/libvirt,datto/libvirt,elmarco/libvirt,eskultety/libvirt,jardasgit/libvirt,datto/libvirt,jardasgit/libvirt,crobinso/libvirt,andreabolognani/libvirt,zhlcindy/libvirt-1.1.4-maintain,cbosdo/libvirt,taget/libvirt,crobinso/libvirt,taget/libvirt