currentTimeDisplay.content changed to currentTimeDisplay.el_

currentTimeDisplay.content changed to currentTimeDisplay.el_ for compatibility with latest version of video.js

.content no longer exists instead _el can be used

![schermafbeelding 2014-03-25 om 10 04 46](https://f.cloud.github.com/assets/1512291/2509867/6fbbb5f2-b3fc-11e3-9c24-fb1c78da2ac6.png)