Fail if FIFO does not have a reader feature breaks snapcast

[ironcrafter54]

Since Snapcast doesn't seem to read the pipe file until something starts writing to it, the newest change means that go-librespot isn't able to
start playing to a pipe that Snapcast is supposed to be reading.

The ideal solution would be to add a config option that let's the user enable or disable this behavior.

This issue is present on versions v0.7.0 and above, and is not present on v0.6.2 and below.