Display "Answer" tab for Goodies in DP Server

This forces an "Answer" tab to display for Goodies results when using duckpan server. 

The #duckbar_home div currently has a class of "zcm__dynamic" which defaults to `display: none`. The below fix removes that class by overwriting it with only "zcm__menu".

I'm not sure if there's a better way of doing this with JS? We could use jQuery to remove the class...

//cc @russellholt