[eslint] prefer-spread

.eslintrc.js

             { 'nestedBinaryExpressions': false }
         ],
 
+        'prefer-spread': 2,
         'require-yield': 2,
         'rest-spread-spacing': 2,
         'sort-imports': 0,

JitsiConnection.js

     // provide the implementation with finer-grained context.
     var x = this.xmpp;
 
-    x.disconnect.apply(x, arguments);
+    x.disconnect(...arguments);
 };
 
 /**

JitsiMediaDevices.js

      * @param {string} event - event name
      */
     emitEvent: function (event) { // eslint-disable-line no-unused-vars
-        eventEmitter.emit.apply(eventEmitter, arguments);
+        eventEmitter.emit(...arguments);
     }
 };
 

modules/RTC/RTCUtils.js

  * @param {Array} [args=[]] arguments for function
  */
 function maybeApply(fn, args) {
-  if (fn) {
-    fn.apply(null, args || []);
-  }
+  fn && fn(...args);
 }
 
 var getUserMediaStatus = {