amend to mcmilk#330, mcmilk#351

…ler (0) - always prefer it for .br format, otherwise `-mmt1` causes that it'd use brotli-mt and the stream is incompatible; `-mmt=n` with `n >= 2` forces multi-threaded compression/decompression (therefore incompatible with standard brotli)

…>=2 to use brotli-mt (the streams are incompatible)

…rotli codec, zip type gets missing because exceeded kNumArcsMax in registering structure g_Arcs)