mod_brotli: Nuke the section about input decompression using mod_brotli

in the documentation.

Currently, mod_brotli only allows dynamic output compression, and doesn't
have the server-side decompression capability.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1790869 13f79535-47bb-0310-9956-ffa450edef68