Enable 3D torches by default in the server example minetest.conf.

resolves #400

patches/subgame/minetest.server-example.conf

@@ -23,6 +23,8 @@ night_time_speed = 60
 # sprint_stamina_drain = .5
 
 bones_position_message = true
+enable_3d_torches = true
+# ^ enable_3d_torches converts nodes, so it must remain `true` after used.
 
 # Set this in world.conf if using codercore/fallback_spawn
 # static_spawnpoint = 0, 11, 0