MULE-6829: cxf_operation is wrong when using proxy-client of a soap 1.1 request
Be smarter about when to add SOAPAction header in cxf so proxy-service works with recent cxf upgrade.
(cherry picked from commit c5e30bd21f9c20a97721dd3767e1816914db463c)
(cherry picked from commit fb29b47444c46f56742385e5a51d15988ddeb6d1)