main.js initAudio() function fix with promise (new standard not deprecated)

[axew3]

`function initAudio() {
// Older browsers might not implement mediaDevices at all, so we set an empty object first
if (navigator.mediaDevices === undefined) {
navigator.mediaDevices = {};
}
// Some browsers partially implement mediaDevices. We can't just assign an object
// with getUserMedia as it would overwrite existing properties.
// Here, we will just add the getUserMedia property if it's missing.
if (navigator.mediaDevices.getUserMedia === undefined) {
navigator.mediaDevices.getUserMedia = function(constraints) {
// First get ahold of the legacy getUserMedia, if present
var getUserMedia = navigator.webkitGetUserMedia || navigator.mozGetUserMedia;
// Some browsers just don't implement it - return a rejected promise with an error to keep a consistent interface
if (!getUserMedia) {
return Promise.reject(new Error('getUserMedia is not implemented in this browser'));
}
// Otherwise, wrap the call to the old navigator.getUserMedia with a Promise
return new Promise(function(resolve, reject) {
getUserMedia.call(navigator, constraints, resolve, reject);
});
}
}

navigator.mediaDevices.getUserMedia({ audio: true, video: false })
.then(gotStream)
.catch(function(err) {
console.log(err.name + ": " + err.message);
});
}`

The initAudio() function on file main.js, should be changed with the above.
See this at:
https://developer.mozilla.org/en-US/docs/Web/API/MediaDevices/getUserMedia