The output of configure now gives something like:

checking wsdl2h version... yes. wsdlh version 2.8.16
2.8.15 detected.

because the AC_WSDL2H macro searches for lines ending with a version number in the output of wsdl2h -h dd, which unfortunately selects also the line

-z5     compatibility up to 2.8.15

Either the regular expression used to select version numbers has to be more specific or just the first occurrence should be taken.