panels_node does drupal_set_message every time export_node_alter is invoked

function panels_node_export_node_alter() gives a warning via drupal_set_message every time it is invoked warning the user that the export method must be save-edit in order to export panel nodes. This is true even if save-edit is in fact the chosen export method, and also even if Panel nodes are excluded from being exportable.

A patch is attached that throws a conditions check around the message. If save-edit is chosen as the export method, or if Panels nodes are not exportable, the message won't show.

Patch was created against the current dev branch.