It was reported that bitbake -D made no mention of which append files it
was using. bitbake -DD does but it makes sense to increase the log level
of this piece of debug information.
[YOCTO #6262]
(Bitbake rev: 5824bf9c6feea05567d155911f4ab2e371911d34)
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>