fix missing leftover Canvas::pick_current_item() which was confusing button release event coordinates

libs/canvas/canvas.cc

@@ -698,7 +698,6 @@ GtkCanvas::on_button_release_event (GdkEventButton* ev)
 	   for scroll if this GtkCanvas is in a GtkCanvasViewport.
 	*/
 
-	pick_current_item (where, ev->state);
 	DEBUG_TRACE (PBD::DEBUG::CanvasEvents, string_compose ("canvas button release @ %1, %2 => %3\n", ev->x, ev->y, where));
 	return deliver_event (reinterpret_cast<GdkEvent*>(&copy));
 }