eager load should be more eager

without this:
````
ubuntu@production-console:~$ dashboard-console
Loading production environment (Rails 4.0.3)
irb(main):001:0> Script.get_from_cache('flappy').script_levels[2].level.specified_autoplay_video
NameError: undefined local variable or method `video_key' for #<Blockly:0x00000005a21c00>
        from /var/lib/gems/2.0.0/gems/activemodel-4.0.3/lib/active_model/attribute_methods.rb:439:in `method_missing'

````

with this:
````
ubuntu@production-console:~/production$ dashboard-console
Loading production environment (Rails 4.0.3)
irb(main):001:0>  s = Script.get_from_cache('flappy').script_levels[2].level.video_key
=> nil

````