Upgrade to new libweb interface

Recent commits from libweb brought a few breaking changes. The one below
affected slcl, so it had to be updated according to the new interface:

commit 98f5f52461b0c1ab1ee3331722bd32e2db9e1d41
Author: Xavier Del Campo <xavier.delcampo@midokura.com>
Date:   Thu Nov 16 12:23:08 2023 +0100

    Split handler_loop from handler_listen

    Some applications might set up a struct handler object to listen on any
    port i.e., 0, but still need a way to determine which port number was
    eventually selected by the implementation.

    Therefore, handler_listen has been reduced to the server initialization
    bit, whereas the main loop has been split into its own function, namely
    handler_loop.

    Because of these changes, it no longer made sense for libweb to write
    the selected port to standard output, as this is something now
    applications can do on their own.

1 files changed, 0 insertions, 0 deletions

diff --git a/libweb b/libweb
-Subproject b71a6174e12b4709acaf8bc151938ba12d2a54f
+Subproject dec953e4f4af89149685c7463c422ccca6174cb