fix 3 fingers pan removal in TrackballControls.js

examples/js/controls/TrackballControls.js

@@ -502,7 +502,6 @@ THREE.TrackballControls = function ( object, domElement ) {
 				_touchZoomDistanceEnd = _touchZoomDistanceStart = Math.sqrt( dx * dx + dy * dy );
 				var x = (event.touches[ 0 ].pageX + event.touches[ 1 ].pageX) / 2;
                 		var y = (event.touches[ 0 ].pageY + event.touches[ 1 ].pageY) / 2;
-                		_panStart = _panEnd = _this.getMouseOnScreen(x, y);
                 		_panEnd.copy( _this.getMouseOnScreen( x, y, _panStart ));
 				break;