Projector: Fixed typo.

src/core/Projector.js

@@ -223,7 +223,7 @@ THREE.Projector = function () {
 			_line.id = object.id;
 			_line.v1.copy( v1 );
 			_line.v2.copy( v2 );
-			_face.z = ( v1.positionScreen.z + v2.positionScreen.z ) / 2;
+			_line.z = ( v1.positionScreen.z + v2.positionScreen.z ) / 2;
 
 			_line.material = object.material;