Editor: Updated ffmpeg to 0.11.6

0.12.* seems to have issues on localhost (DOMException: Failed to construct 'Worker')

editor/index.html

@@ -23,7 +23,7 @@
 		<script src="js/libs/esprima.js"></script>
 		<script src="js/libs/jsonlint.js"></script>
 
-		<script src="https://cdn.jsdelivr.net/npm/@ffmpeg/[email protected]0.1/dist/ffmpeg.min.js"></script>
+		<script src="https://cdn.jsdelivr.net/npm/@ffmpeg/[email protected].6/dist/ffmpeg.min.js"></script>
 
 		<link rel="stylesheet" href="js/libs/codemirror/addon/dialog.css">
 		<link rel="stylesheet" href="js/libs/codemirror/addon/show-hint.css">