COMP: including only vcl_complex leads to compilation error if we use...

COMP: including only vcl_complex leads to compilation error if we use vcl_abs(double) later without including it explicitely
(transplanted from 0b91b902d6fe829db8525297fa66ee80e621006f)

Code/SARPolarimetry/otbPolarimetricSynthesisFunctor.h

@@ -18,7 +18,7 @@
 #ifndef __otbPolarimetricSynthesisFunctor_h
 #define __otbPolarimetricSynthesisFunctor_h
 
-
+#include "otbMath.h"
 #include "vcl_complex.h"
 #include "itkFixedArray.h"