Update ArcballControls.html

docs/examples/en/controls/ArcballControls.html

@@ -252,11 +252,6 @@
 			Keyboard modifiers can be specified as 'CTRL', 'SHIFT' or null if not needed.
 		</p>
 
-		<h3>[method:undefined setTarget] ( [param:Float x], [param:Float y], [param:Float z] )</h3>
-		<p>
-			Set the trackball center point.
-		</p>
-
 		<h3>[method:Boolean unsetMouseAction] ( mouse, key )</h3>
 		<p>
 			Removes a mouse action by specifying its mouse/key combination.<br><br>