Add compatibility for libshout >= 2.4.2 shout_open return values
Libshout changed return values for shout_open. Problem is described in this issue: #848 (closed)
In libshout, the problem is fixed in the nonblocking example application in a similar way, as mentioned by the author in this issue: https://gitlab.xiph.org/xiph/icecast-libshout/-/issues/2316