Don't connect to pulseaudio with PA_CONTEXT_NOFAIL

NOFAIL means we don't fail if the daemon is not available when `pa_context_connect()` is called and instead enter `PA_CONTEXT_CONNECTING` state and wait for the daemon to appear.

So currently if pulseaudio isn't running or available, ponymix will just block and wait. Since a lot of people use ponymix bound to their volume keys, this could potentially mean spawning 100s of processes before actually catching on that things aren't working.

`PA_CONTEXT_NOFLAGS` was introduced in 0.9.19. Its really just 0.

Signed-off-by: Simon Gomizelj <simongmzlj@gmail.com>