Add doc and comment out unrelated line that is offending OSX

Author: shinrich

doc/admin-guide/files/records.yaml.en.rst

@@ -698,6 +698,7 @@ HTTP Engine
    tr-out                      Outbound transparent.
    tr-pass                     Pass through enabled.
    mptcp                       Multipath TCP.
+   allow-plain                 Allow failback to non-TLS for TLS ports
    =========== =============== ========================================
 
 *number*
@@ -722,6 +723,8 @@ ssl
 
    Not compatible with: ``blind`` and ``quic``.
 
+   ``allow-plain`` allows a failback to non SSL for such ports.
+
 quic
    Require QUIC termination for inbound connections. SSL :ref:`must be configured <admin-ssl-termination>` for this option to provide a functional server port.
    **THIS IS EXPERIMENTAL SUPPORT AND NOT READY FOR PRODUCTION USE.**
@@ -780,6 +783,9 @@ mptcp
 
    Requires custom Linux kernel available at https://multipath-tcp.org.
 
+allow-plain
+   For TLS ports, will fall back to non-TLS processing if the TLS handshake fails.
+
 .. topic:: Example
 
    Listen on port 80 on any address for IPv4 and IPv6.::

proxy/http/HttpSM.cc

@@ -2352,7 +2352,7 @@ HttpSM::add_to_existing_request()
       // bytes are received back
       this->t_state.set_connect_fail(EIO);
       ip_iter->second->connect_sms.insert(this);
-      Debug("http_connect", "Add entry to connection queue. size=%" PRId64, ip_iter->second->connect_sms.size());
+      // Debug("http_connect", "Add entry to connection queue. size=%" PRId64, ip_iter->second->connect_sms.size());
       retval = true;
       break;
     }