python: Fix to support the python module _bsddb built with db 5.3
_bsddb module in python 2.7 could be built only with db version
between 4.1 and 4.7. A patch was added to avoid build warning
about this for [YOCTO #1937] but not actually fixed it.
This patch enable _bsddb module be built with db 5.3, and remove
--disable-statistics from the DB5_CONFIG to fix segmentation fault
when using _bsddb module in python.
[YOCTO #2749]
Signed-off-by: Jackie Huang <jackie.huang@windriver.com> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
