Error with opentok 2.14

After upgrading opentok version to 2.14, we see this error:

![image](https://user-images.githubusercontent.com/19624195/41538965-eac6b108-72e2-11e8-8c14-61b8b3581225.png)

Env:
`angular-opentok`: 2.1.2
`opentok`: 2.14.0