Fix Firefox audio not playing

[masonblier]

This check for AudioContext state does not work in Firefox as unlike Chromium, Firefox does not automatically set the initial state of the AudioContext to running. Removing this check seems to cause no problems as the audio state is set to disabled by default.

More details about the difference of the initial AudioContext state between browsers is discussed here: WebAudio/web-audio-api#2218

This fixes issue: #463

@kixelated

[kixelated]

I don't know the ramifications of removing this check, but I'll test it and figure out an alternative if needed.

[masonblier]

Thanks for the merge! I suspect this issue might arise if the audio is enabled by default, but it seems that unlike Video, the Audio class doesn't get signals when broadcast fetchCatalog completes, so the Audio doesn't get started until another signal is received (such as unmuting). I couldn't figure out why Audio doesn't update from the fetchCatalog changes, it does subscribe to the signal, but the function runDecoder never gets called. So I was unable to create a scenario where this would trigger an error.