system: default to vm.numa.disabled=1

NUMA has performance drawbacks and seems incomplete too.
We're going to assess impact hereby on the general approach,
but from early testing this increases network throughput
considerably in some scenarios.

src/etc/inc/system.inc

@@ -128,6 +128,7 @@ function system_sysctl_defaults()
         'vfs.read_max' => [ 'default' => '32' ],
         'vfs.zfs.dirty_data_sync_percent' => [ 'default' => '5', 'required' => true ],
         'vfs.zfs.txg.timeout' => [ 'default' => '90', 'required' => true ],
+        'vm.numa.disabled' => [ 'default' => '1', 'required' => true ],
         'vm.pmap.pti' => [ 'default' => '1' ],
     ];
 }