Remove the "Submit" button from the node/x/webform tab when there are no components yet

When there are no components yet on a Webform node and you visit node/x/webform (the component listing) there are two buttons on the page, "Submit" and "Add". Submit generally only controls updating the position of components in relation to each other, while Add obviously adds the component to the webform. This is confusing and completely unnecessary that we have two buttons when there is only one component in the form.