mpm_winnt: remove 'data' AcceptFilter in favor of 'connect'

The 'data' AcceptFilter optimization instructs Windows to wait until
data is received on a connection before completing the AcceptEx
operation. Unfortunately, it seems this isn't performed atomically --
AcceptEx "partially" accepts the incoming connection during the wait for
data, leaving all other incoming connections in the accept queue. This
opens the server to a denial of service.

Since the fix for this requires a substantial rearchitecture (likely
involving multiple outstanding calls to AcceptEx), disable the 'data'
filter for now and replace it with 'connect', which uses the AcceptEx
interface but does not wait for data.

Users running prior releases of httpd on Windows should explicitly move
to a 'connect' AcceptFilter in their configurations if they are
currently using the default 'data' filter.

Many thanks to mludha, Arthur Ramsey, Paul Spangler, and many others for
their assistance in tracking down and diagnosing this issue.

PR: 59970

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1758307 13f79535-47bb-0310-9956-ffa450edef68