Bug 911055 - [zffos1.1][P3][Dailer]DuT doesn allow to dial a <<pause>>

Example of the function call method that I mentioned above:
```js
call.onconnected = function connectedCB() {
  var dtmfDigits = this._getDtmfFromNumber(number);
  if (dtmfDigits) {
    // ...
  }
};