http: remove a needless comment
http: remove a needless comment

We don't implement keep-alive for groonga-server-http. It's implemented
in groonga-httpd.

hiroyuki-sato/groonga,naoa/groonga,cosmo0920/groonga,cosmo0920/groonga,komainu8/groonga,kenhys/groonga,hiroyuki-sato/groonga,hiroyuki-sato/groonga,groonga/groonga,naoa/groonga,redfigure/groonga,komainu8/groonga,komainu8/groonga,naoa/groonga,naoa/groonga,hiroyuki-sato/groonga,redfigure/groonga,groonga/groonga,kenhys/groonga,kenhys/groonga,naoa/groonga,redfigure/groonga,cosmo0920/groonga,cosmo0920/groonga,kenhys/groonga,groonga/groonga,kenhys/groonga,redfigure/groonga,komainu8/groonga,naoa/groonga,redfigure/groonga,komainu8/groonga,redfigure/groonga,hiroyuki-sato/groonga,kenhys/groonga,cosmo0920/groonga,komainu8/groonga,hiroyuki-sato/groonga,groonga/groonga,cosmo0920/groonga,redfigure/groonga,groonga/groonga,komainu8/groonga,redfigure/groonga,hiroyuki-sato/groonga,groonga/groonga,hiroyuki-sato/groonga,groonga/groonga,komainu8/groonga,kenhys/groonga,kenhys/groonga,cosmo0920/groonga,groonga/groonga,naoa/groonga,cosmo0920/groonga,naoa/groonga