increment $VERSION after 6.15 release

Author: oalders

Changes

@@ -1,5 +1,7 @@
 Revision history for HTTP-Daemon
 
+{{$NEXT}}
+
 6.15      2023-02-22 22:02:46Z
   - Fix CVE-2022-31081: Inconsistent Interpretation of HTTP Requests
     Correctly handle multiple Content-Length headers and its variants

lib/HTTP/Daemon.pm

@@ -5,7 +5,7 @@ package HTTP::Daemon;
 use strict;
 use warnings;
 
-our $VERSION = '6.15';
+our $VERSION = '6.16';
 
 use Socket ();
 use IO::Socket::IP;