When we are trying to use plusesink and pulsesrc in an environment with
pulse deamon off.
And found for pulsesrc, it will auto start the pulseaudio daemon, but
for pulsesink, it will not.
And I see in pulsesink.c it set the flag PA_CONTEXT_NOAUTOSPAWN when
try to connect to the pulse server.
I'm not sure why here in pulsesink set this flag to avoid autospawn the
deamon. If I change it to PA_CONTEXT_NOFLAGS, will there be any