vtkAMREnzoReader:: Properly initialize ivar ConvertCGS in the constructor

Change-Id: Iaab6fcb6b7e1044f9f22dd3487df598e66e3b239
Merge topic 'fix-vtkAMREnzoReader-ConvertCGS-initialization' into master

0e316bde vtkAMREnzoReader:: Properly initialize ivar ConvertCGS in the constructor