set layer2 support after successful macsuck, similar to arpnip does for l3

lib/App/Netdisco/Worker/Plugin/Macsuck/Nodes.pm

@@ -207,6 +207,7 @@ register_worker({ phase => 'store',
     $device->ip, $archived;
 
   $device->update({last_macsuck => \$now});
+  $device->update({layers => \[q{overlay(layers placing '1' from 7 for 1)}]});
 
   my $status = $job->best_status;
   return Status->$status("Ended macsuck for $device");