Removing the 1.6.X recipes, since there is a new version 1.8.X recipes,
and hope that all projects already upgraded their premirror caches to
use new format
(From OE-Core rev: 65c4dcbefbe118eb1b04335d7d6171236a1315c2)
Signed-off-by: Roy Li <rongqing.li@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>