Revert writing empty parens for expanded nav prop in 4.0 response

[mikepizzo]

PR #1286 fixed issue #1265 (along with others) by including an empty parens in the ContextUrl for expanded entities with no expand options specified.

This is required in 4.01 and suggested in 4.0.

Although empty parens should be supported for 4.0, and clients using our 4.0 libraries are able to consume this, we have at least two incidents of customers parsing the contextUrl on their own which are not expecting the empty parens in this case.

To be safe, we should make adding the empty parens written only for 4.01 responses.

[mikepizzo]

Doesn't seem worth fixing at this point.