Restore comment about LimitRequestBody vs proxied responses.

ResponseFieldSize actually applies to headers (not body), so the comment was
valid but did match the code (addressed by r1829642 still).



git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1829643 13f79535-47bb-0310-9956-ffa450edef68