Dynamic client returns a T when it should return a List<T>

This only affects unwrappable operation (op.isUnwrappedCapable() && !op.isUnwrapped() is true) that returns a sequence of objects.
I only tested on version 2.1.4 but it may affect other versions as well given that the codebase has not changed.

This issue can be reproduced with the public ws: http://www.wikipathways.org/wpi/webservice/webservice.php?wsdl. The operation listOrganisms returns a String instead of a List<String>.

Fyi, the default implementation of the jaxrpc spec returns String[].