Unfinished speakOut() will be interrupt by another call and never gets the 'tts-end' callback

[jammind]

I fixed it by replacing Line 46
let language = options && options.language ? options.language : 'en-US' // Line 46
with the following codes

    if (typeof Speech.__currentSpeakOutSuccess == 'function') {
        success('tts-end')
        return
    }
    Speech.__currentSpeakOutSuccess = onMessage
    exec(onMessage, error, SPEECH, API_LIST.SPEAK_OUT, [message, pitchRate, speechRate, language])

    function onMessage (msg) {
        if (msg == 'tts-end') delete Speech.__currentSpeakOutSuccess
        success(msg)
    }