`stop` appears to break the polyfill when continuously listening

[JamesBrill]

Steps

• Set continuous property to true
• Call start
• Call stop

Expected behaviour

• Transcription stops
• Microphone is turned off
• When called again, start will resume transcription

Actual behaviour

• Transcription stops as expected
• Microphone is not turned off
• When called again, start will not resume transcription. As a result, the page must be refreshed to re-enable voice functionality

Notes

• abort enables the expected behaviour - this is the current workaround I'll be recommending to consumers of react-speech-recognition, which integrates with this polyfill
• Tested on Chrome, Safari, and Firefox (all relatively recent versions) on MacOS