[tlbuild] lzma 4.32.6 released

[Karl Berry]

Naturally, the day after I asked for lzma binaries, Lasse released a new
version.  You can get 4.32.6 from http://tukaani.org/lzma/download or
from the TL source repo; I've updated Build/source/utils/lzma-utils.

Although ordinarily I wouldn't worry about minor version skew, lzma is
so new and has had so many parsing/format fixes, I'd like to distribute the
same version for all binaries.

Thanks,
Karl