configure: Rely on `AC_CANONICAL_HOST' to determine the Nix system name.
configure: Rely on `AC_CANONICAL_HOST' to determine the Nix system name.

This should be more robust and also plays better with
cross-compilation---it uses the host name, instead of using the build
name.

layus/nix,rycee/nix,rycee/nix,jcumming/nix,edolstra/nix,vizanto/nix,rowhit/nix,ehmry/nix,edolstra/nix,puffnfresh/nix,zimbatm/nix,rycee/nix,offlinehacker/nix,garbas/nix,joelmo/nix,dtzWill/nix,dtzWill/nix,vizanto/nix,vcunat/nix,nbp/nix,ttuegel/nix,zimbatm/nix,rowhit/nix,edolstra/nix,garbas/nix,vizanto/nix,offlinehacker/nix,layus/nix,bjornfor/nix,garbas/nix,gridaphobe/nix,aucampia/nix,ehmry/nix,dtzWill/nix,joelmo/nix,ttuegel/nix,garbas/nix,gridaphobe/nix,vcunat/nix,acowley/nix,ttuegel/nix,gebner/nix,acowley/nix,dezgeg/nix,gebner/nix,tchajed/nix,dezgeg/nix,jcumming/nix,ehmry/nix,nbp/nix,offlinehacker/nix,ehmry/nix,NixOS/nix,tchajed/nix,NixOS/nix,gebner/nix,jcumming/nix,bjornfor/nix,NixOS/nix,dezgeg/nix,shlevy/nix,dtzWill/nix,aucampia/nix,wmertens/nix,rycee/nix,NixOS/nix,edolstra/nix,joelmo/nix,ysangkok/nix,bennofs/nix,ttuegel/nix,zimbatm/nix,puffnfresh/nix,layus/nix,shlevy/nix,bennofs/nix,nbp/nix,vizanto/nix,edolstra/nix,tchajed/nix,puffnfresh/nix,ysangkok/nix,peti/nix,joelmo/nix,peti/nix,nbp/nix,pikajude/nix,vcunat/nix,jcumming/nix,acowley/nix,peti/nix,NixOS/nix,layus/nix,peti/nix,aucampia/nix,acowley/nix,layus/nix,gridaphobe/nix,aucampia/nix,gridaphobe/nix,bjornfor/nix,ehmry/nix,bjornfor/nix,zimbatm/nix,shlevy/nix,offlinehacker/nix,pikajude/nix,puffnfresh/nix,rycee/nix,tchajed/nix,rowhit/nix,gebner/nix,shlevy/nix,peti/nix,rowhit/nix,bennofs/nix,vcunat/nix,dezgeg/nix,pikajude/nix,wmertens/nix,bennofs/nix,wmertens/nix,ehmry/nix,shlevy/nix,garbas/nix,wmertens/nix,ysangkok/nix,dezgeg/nix,dtzWill/nix