apt-native: use open instead of file (unsuppported in python3)
apt-native: use open instead of file (unsuppported in python3)

http://stackoverflow.com/questions/16736833/python-nameerror-name-file-is-not-define

Signed-off-by: Toshiko YOSHIDA <311de952d79aff7d5c68e1437a41a732e1c05c82@toshiba.co.jp>

tienlee/meta-debian,nghiaht-tsdv/meta-debian,tienlee/meta-debian,meta-debian/meta-debian,tienlee/meta-debian,nghiaht-tsdv/meta-debian,tienlee/meta-debian,meta-debian/meta-debian,tienlee/meta-debian,nghiaht-tsdv/meta-debian,meta-debian/meta-debian,meta-debian/meta-debian,nghiaht-tsdv/meta-debian,nghiaht-tsdv/meta-debian,tienlee/meta-debian,nghiaht-tsdv/meta-debian,meta-debian/meta-debian,meta-debian/meta-debian