Fix ky typo with ifftshift -> fftshift

Author: ChristopherMayes

pmd_beamphysics/wavefront/wavefront.py

@@ -296,7 +296,7 @@ def kyvec(self):
         """
         Array of ky (transverse wavenumber) values in rad/m.
         """
-        return 2 * pi * ifftshift(fftfreq(self.ny, d=self.dy))
+        return 2 * pi * fftshift(fftfreq(self.ny, d=self.dy))
 
     @property
     def kymin(self):