Log Message:
libshout: update to 2.4.6.

libshout 2.4.6 (20220410)

* Fixed pkg-config file (#2329)
* Made vorbis an optional codec
* Do not pass to small headers to libspeex
  (see also the same mirror-patch in Icecast)
* Updated documentation, mostly in regard of making it clearer
  which functions are now obsoleted
* General code cleanup
* Added compiler warnings about obsoleted functions and
  ignored return values
* Replaced old shout_set_metadata() with new shout_set_metadata_utf8()
* Added support for plain text streaming
* Fixed shout_set_metadata*() sometimes returning SHOUTERR_RETRY (#2328)
* Workaround old clients by emulating SHOUTERR_RETRY with SHOUTERR_BUSY (#2316)
* Remove our re-implementation of X509_check_host()
* Allow to disable building tools (#2331)