Case where brotli quality 9 compresses better than quality 11

I found a test case where brotli with quality 9 compresses better than with quality 11. This seemed worth reporting in case there might be some convenient way to detect and handle this case (short of compressing the whole file both ways to check).

Test case and compressed versions: [brotli-test.tar.gz](https://github.com/google/brotli/files/417342/brotli-test.tar.gz)

(This test case came from a locally modified version of [bsdiff](http://www.daemonology.net/bsdiff/) that doesn't use bzip2 internally, so that I could test it with brotli. The bsdiff goes from jquery-2.2.3.min.js to jquery-2.2.4.min.js .)

Compressing jquery.ubsdiff with brotli quality 11 produces 264 bytes; compressing with quality 9 produces 252 bytes.