Fix an issue with missing soapAction tag
Fix an issue with missing soapAction tag

method.soapAction is initialized to an empty so the else
case which correspond to a missing soapAction tag  in the
wsdl is unreachable. This fix just replace the undefined or null
check by a negative check.

Signed-off-by: Jerome Dassonville <2e19acc66a7d5ee3638e67e19659f4e1520ccb45@worldline.com>

worldline/node-soap,yodeyer/node-soap