Update Box3.js

Added missing semicolon.

src/math/Box3.js

@@ -29,7 +29,7 @@ THREE.Box3.prototype = {
 
 		for ( var i = 0, il = points.length; i < il; i ++ ) {
 
-			this.expandByPoint( points[ i ] )
+			this.expandByPoint( points[ i ] );
 
 		}