Create /home with the right permissions

Without this, it will be created with 700 permissions.

nixos/modules/config/users-groups.nix

···
 
     system.activationScripts.users = stringAfter [ "stdio" ]
       ''
+        install -m 0700 -d /root
+        install -m 0755 -d /home
+
         ${pkgs.perl}/bin/perl -w \
           -I${pkgs.perlPackages.FileSlurp}/lib/perl5/site_perl \
           -I${pkgs.perlPackages.JSON}/lib/perl5/site_perl \
           ${./update-users-groups.pl} ${spec}
-
-        install -m 0700 -d /root
       '';
 
     # for backwards compatibility