icecast: update to 2.4.4.

Icecast 2.4.4
-----------------------------------------------------------------------------
We are releasing Icecast 2.4.4, an important bugfix-only release.
We recommend upgrading for increased stability and compatibility!

## Fixes

- Fix: Fixed segfault in htpasswd auth if no filename is set
- Fix: Do not report hashed user passworts in user list.
- Fix two mistakes in the default config's comments
- Add log message for succesful streamlist requests
- Fix: update_from_master() for receiving HTTP/1.1
- Fix: Spelling, thanks to Ukikie
- Fix: Fixed a segfault when xsltApplyStylesheet() returns error
- Fix: Do not segfaul on bad Opus streams
- Fix: Corrected response and fixed TLS for 416 Request Range Not Satisfiable
  responses
- Fix: TLS for ICECAST_PROTOCOL_SHOUTCAST source clients
  and investigating the bug.
- Fix: global listener count could be negative under certain circumstances
  Thanks a lot to Simeon V旦lkel (0xBD4E031CDB4043C9) for reporting
  and investigating the bug.
- Fix: Send "Content-Length: 0" on 100-continue
- Fix: Do not send 100-continue in plain text over TLS sockets
- Fix: Added needed code to announce Opus streams as such to yp.
- Fix: Avoid invalid locking in signal handlers.
- Workaround: avoid libspeex printing warnings on Opus streams.
- Fix: Fixed regression introduced by r19250.
  The fix checks if the source client is actually
  known before printing it's IP-Address.
- Fix: do not allow unescaped strings in XML output.

## Known issues

-  HTTP PUT implementation currently doesn't support chunked encoding yet.
-  HTTP PUT with "Expect: 100-Continue" receives first a "100" and soon
    after a "200", instead of the "200" at the end of transmission.
-  Caution should be exercised when using `<on-connect>` or
    `<on-disconnect>`, as there is a small chance of stream file descriptors
    being mixed up with script file descriptors, if the FD numbers go above
    1024. This will be further addressed in the next Icecast release.
-  Don't use comments inside `<http-headers>` as it will
    prevent processing of further `<header>` tags.
-  Webinterface shows Login when using just `stream_auth`.

(wiz)