The dialog references are all in builder.py. We remove the useless "import" in image configuration page.
(Bitbake rev: 804f35e6864aeae2bb02550d9eb34120bbb60fa0)
Signed-off-by: Shane Wang <shane.wang@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>