Using the threading module interacts badly with multiprocessing used elsewhere
in bitbake under certain machine loads. This was leading to bitbake hanging on
Ctrl+C when the PR Server was being used.
This patch converts it to always use the daemonize code which
then means the threading code isn't required.
[YOCTO #3742]
(Bitbake rev: 2d0bbd9398ab839bd2d1e29e50b25d52efb1ce2a)
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>