fix: audio cannot play after unplugging headphones on IOS

[xiaobao66]

Fixes #1355
On iOS, when you unplug headphones, its policy will suspend any AudioContext and Howler.ctx.state is changed to 'suspended'.
But In the _autoResume function, AudioContext can only be resumed when Howler state is 'suspended' or Howler state is 'running' and Howler.ctx.state is 'interrupted':

howler.js/src/howler.core.js

Line 524 in f128f9d

} else if (self.state === 'suspended' || self.state === 'running' && self.ctx.state === 'interrupted') {

Originally posted in #1355 (comment)

[paulfernandes]

@goldfire, is there any plan to merge this into master any time soon? This would be useful to solve a currently known issue.