bug in cmapconv.py parse_colormap

There is a typo/oversight in the if statement that confirms the colormap data is valid. It does not affect the output, but I noticed it when looking at the code and wanted to point it out.

if ( c[0] < 0 or c[0] > 15 or c[0] < 0 or c[1] > 15 or

This should be revised as follows:

if ( c[0] < 0 or c[0] > 15 or c[1] < 0 or c[1] > 15 or