Change amount of Nodes on Packaging Jenkins

OSX Mini's will be removed from pkg-jenkins. OSX 10.7/10.8/10.9 are
used only for RTA.

Also one Ubuntu node added for b2qt tests.

Change-Id: If0dc195f28ebc0010d71f8188706a7a729648c60
Reviewed-by: Tony Sarajärvi <tony.sarajarvi@digia.com>