Prepare for 2.3.0

example.cfg

@@ -55,6 +55,9 @@ syslog_facility: "auth";
 # is_unix: listen in the UNIX socket domain (default is TCP)
 # keepalive: set TCP_KEEPALIVE
 # max_connections: drop incoming connections after this count
+# proxyprotocol: [true|false]: this endpoint expects
+#   proxyprotocol headers on incoming connections. Refer to
+#   doc/proxyprotocol.md
 listen:
 (
     { host: "thelonious"; port: "443"; max_connections: 5; },