corrected apache modules example

[G3z]

I think the example is clearer

[danhunsaker]

This is the correct direction - the example is currently incomplete! - but deviates from the way documentation examples are given elsewhere in the same file, as well as throughout other Nanobox documentation. Namely, the example should list the default values used by the engine if the option isn't explicitly given in the boxfile. Switch that over, and this should be merged pretty easily.