NullPointerException for request with no SOAP body

SaajSoapEnvelope now throws an exception when the SOAP envelope contains
no SOAP body.

Issue: SWS-887

Author: poutsma

spring-ws-core/src/main/java/org/springframework/ws/soap/saaj/SaajSoapEnvelope.java

@@ -51,6 +51,9 @@ public SoapBody getBody() {
 		if (body == null) {
 			try {
 				SOAPBody saajBody = getSaajEnvelope().getBody();
+				if (saajBody == null) {
+					throw new SaajSoapBodyException("SAAJ SOAP message has no body");
+				}
 				if (saajBody.getElementQName().getNamespaceURI()
 						.equals(SoapVersion.SOAP_11.getEnvelopeNamespaceUri())) {
 					body = new SaajSoap11Body(saajBody, langAttributeOnSoap11FaultString);