Fix audio duplication after pause-restart-resume
Fix audio duplication after pause-restart-resume

Fixes #538

Thanks @josalmi

yupaul/phaser-ce,photonstorm/phaser-ce,photonstorm/phaser-ce,yupaul/phaser-ce,yupaul/phaser-ce,yupaul/phaser-ce,photonstorm/phaser-ce,photonstorm/phaser-ce