s/http_workspace/sess_workspace/

Fixes #557


git-svn-id: http://www.varnish-cache.org/svn/trunk/varnish-cache@4329 d4fa192b-c00b-0410-8231-f00ffab90ce4

bin/varnishd/varnishd.1

@@ -520,7 +520,7 @@ and
 are specified, the latter should be specified last.
 .Pp
 The default is "nogroup".
-.It Va http_workspace
+.It Va sess_workspace
 The size of the per-session workspace for HTTP protocol data.
 For performance reasons, this space is preallocated, so any change to
 this parameter will only apply to new client sessions.