The initial hash serve loop exits in the case where interrupts are present
but probably checks a bit too often. Tweak that and also allow the slow
rehash loop to break on interrupt, improving bitbake Ctrl+C response.
(Bitbake rev: ca2f63d84b90cbd99936c9d7815d912d9019a594)
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Signed-off-by: Steve Sakoman <steve@sakoman.com>