Corrected a typo in the script making Gadget ICs

examples/make_gadget_ic.py

@@ -44,5 +44,5 @@ grp.attrs.create("MassTable", np.array([0.,0.,0.,0.,0.,0.]), dtype='d')
 grp.attrs.create("NumFilesPerSnapshot", 1., dtype='i')
 grp.attrs.create("NumPart_ThisFile", np.array([0,numPart,0,0,0,0]), dtype='i')
 grp.attrs.create("NumPart_Total", np.array([0,numPart,0,0,0,0]), dtype='i')
-grp.attrs.create("NumPart_HighWord", np.array([0,0,0,0,0,0]), dtype='i')
+grp.attrs.create("NumPart_Total_HighWord", np.array([0,0,0,0,0,0]), dtype='i')
 grp.attrs.create("Time", 0., dtype='d')