Change liberty's reno page to use the tag
Change liberty's reno page to use the tag

As liberty was EOL'd and the stable/liberty branch was removed, let's
use liberty-eol tag instead.

Change-Id: I9e30bc3334b99b4a22f870c64b3daba92b66ea0d

NaohiroTamura/ironic,SauloAislan/ironic,pshchelo/ironic,openstack/ironic,openstack/ironic,NaohiroTamura/ironic,pshchelo/ironic,SauloAislan/ironic