misc/make-vmu: convert to Python 3 with 2to3
misc/make-vmu: convert to Python 3 with 2to3

Signed-off-by: Benjamin Gilbert <55d1d0083477f6dd5757d8929dd3b9e09d80bd84@cs.cmu.edu>

openslide/openslide,openslide/openslide,openslide/openslide,openslide/openslide