[docs] gzip compression level

[Wolfgang Rohdewald]

http://docs.python.org/library/gzip.html

says level is 1..9

actually 0 works too - this the original uncompressed data
but with a gzip header.

I need level 0 for getting a smaller git repository with many
svgz files which have often been edited
(the file names and types cannot be changed)

So - is this a documentation bug or have I just been lucky?

-- 
Wolfgang