bitbake: bitbake: Drop futures usage since we're python 3

(Bitbake rev: bf25f05ce4db11466e62f134f9a6916f886a93d9)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

bitbake/lib/bb/parse/ast.py

@@ -21,8 +21,7 @@
 # with this program; if not, write to the Free Software Foundation, Inc.,
 # 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 
-from __future__ import absolute_import
-from future_builtins import filter
+
 import re
 import string
 import logging