Manual update button hidden if no plugins to update availabe.

The 'Update now' button in the plugin manager is not visible on the 'Available plugins', if there are no updates. One hsa to switch to the advanced tab to find it.
As soon as at least one update is available, the button appears.

Probably it gets hidden together with the "update plugins" button as the complete bottom-sticker div is gone.

(note: component set to core, as I could find a plugin manager comp.)