Increase default max number of headers
Increase default max number of headers

People have been running into the maximum number of headers limitation
more and more lately, so increase this a little bit.  It is a
per-thread overhead, so it should not make any real difference when it
comes to memory consumption.

git-svn-id: 7d4b18ab7d176792635d6a7a77dd8cbbea8e8daa@4422 d4fa192b-c00b-0410-8231-f00ffab90ce4

CartoDB/Varnish-Cache,wikimedia/operations-debs-varnish,wikimedia/operations-debs-varnish,ssm/pkg-varnish,ssm/pkg-varnish,ssm/pkg-varnish,wikimedia/operations-debs-varnish,ssm/pkg-varnish,wikimedia/operations-debs-varnish,wikimedia/operations-debs-varnish,ssm/pkg-varnish,CartoDB/Varnish-Cache,CartoDB/Varnish-Cache