This commit adds support for proxying multicast streams through a UDPxy
server. If the stream is multicast, and a udpxy server is set in the
configuration, then the channel URL is rewritten to use the UDPxy
service configured.
The stream URL rewriting is done regardless of the buffer option set.
Signed-off-by: 5Ub-Z3r0 <1673590+5Ub-Z3r0@users.noreply.github.com>
