ctdb-build: Drop lib/util from includes

ctdb-build: Drop lib/util from includes

In is unnecessary and can accidentally cause lib/util/time.h to be
found instead of /usr/include/time.h.  The only things depending on it
were bare includes of db_wrap.h and a bare include of dlinklist.h,
which are both gone now.

Signed-off-by: Martin Schwenke <martin@meltin.net>
Reviewed-by: Amitay Isaacs <amitay@gmail.com>