Replace two OSX 10.7 with OSX 10.8 in Packaging Jenkins

We need more OSX 10.8 in pkg-jenkins. We can get these by replacing
two OSX 10.7 with OSX 10.8

Change-Id: Ie599f29b1774111d0254c6476c9a235feffc6bc1
Reviewed-by: Tony Sarajärvi <tony.sarajarvi@digia.com>