Example: Fix canvas shapes particle sparks breakage

- #5071
- Due to object.position being immutable

examples/canvas_particles_shapes.html

@@ -204,6 +204,12 @@
 
 				sparksEmitter.addCallback("created", onParticleCreated);
 				sparksEmitter.addCallback("dead", onParticleDead);
+				sparksEmitter.addCallback("updated", function( particle ) {
+
+					particle.target.position.copy( particle.position );
+
+				});
+
 				sparksEmitter.start();
 
 				// End Particles