WSTrustResponseWriter output context as empty string

[matejsp]

request is:

 <trust:RequestSecurityToken xmlns:trust="http://docs.oasis-open.org/ws-sx/ws-trust/200512">

response is:

  <wst:RequestSecurityTokenResponseCollection xmlns:wst="http://docs.oasis-open.org/ws-sx/ws-trust/200512">
     <wst:RequestSecurityTokenResponse Context="">

but should be:

  <wst:RequestSecurityTokenResponseCollection xmlns:wst="http://docs.oasis-open.org/ws-sx/ws-trust/200512">
    <wst:RequestSecurityTokenResponse>

FIX inside WSTrustResponseWriter.java (added if (context != null) { ... }):

private void write(RequestSecurityTokenResponse response) throws ProcessingException {
    // write the response element and the context attribute.
    StaxUtil.writeStartElement(this.writer, WSTrustConstants.PREFIX, WSTrustConstants.RSTR, WSTrustConstants.BASE_NAMESPACE);
    String context = response.getContext();
    if (context != null) {
        StaxUtil.writeAttribute(this.writer, WSTrustConstants.RST_CONTEXT, context);
    }

[anilsaldhana]

Please send a pull request.