Library runs twice and breaks element

Problem/Motivation

Library runs twice for fields with MediaElement.js Video field formatter causing video to break (screenshot attached).

Steps to reproduce

• Install and configure this module.
• Configure a file field with the MediaElement.js Video field formatter.

Proposed resolution

Change selector from: ".mediaelementjs" to "video.mediaelementjs,audio.mediaelementjs".

Remaining tasks

N/A

User interface changes

N/A

API changes

N/A

Data model changes