fix type warning for VS9_x64

Error report was:
src\utils\color_cache.c(48) : warning C4334: '<<' : result of 32-bit shift implicitly converted to 64 bits (was 64-bit shift intended?)

Change-Id: I93463ba7cd94faf1cf04986acbfaa06b62700d26
lossless: entropy clustering for high qualities.

Tested on 1000 pngs corpus with quality 90-100 it gives ~0.15% improvement
in compression density and ~7% speed up.

Change-Id: I460f56c96707edb3c1f0b51a024e5122e10458df