[CXF-5147] Don't NPE if using a primitive for a holder. If null, don't call the setter so whatever is the default in the wrapper object would end up being used. (basically, same behavior as when a BARE method is used)

git-svn-id: https://svn.apache.org/repos/asf/cxf/trunk@1508965 13f79535-47bb-0310-9956-ffa450edef68