Removes unused code from web/compatibility.js

web/compatibility.js

@@ -571,7 +571,6 @@ if (typeof PDFJS === 'undefined') {
   }
   window.requestAnimationFrame =
     window.mozRequestAnimationFrame || window.webkitRequestAnimationFrame ||
-    window.oRequestAnimationFrame || window.msRequestAnimationFrame ||
     (function fakeRequestAnimationFrame(callback) {
       window.setTimeout(callback, 20);
     });