(PDB-2640) Add comment about gzip decompression and buffering perf
(PDB-2640) Add comment about gzip decompression and buffering perf

This commit adds a comment to the code where a decompression stream is
wrapped around the command input stream about how it's best for
performance to not wrap another buffered input stream between the
original command input stream and the decompression stream.

mullr/puppetdb,puppetlabs/puppetdb,rbrw/puppetdb,puppetlabs/puppetdb,puppetlabs/puppetdb,rbrw/puppetdb,mullr/puppetdb,mullr/puppetdb,puppetlabs/puppetdb,mullr/puppetdb,rbrw/puppetdb,rbrw/puppetdb,mullr/puppetdb,rbrw/puppetdb,puppetlabs/puppetdb