typing: disable import error warnings that are already handled
I'm assuming that the cffi ones are handled somewhere, but the others definitely
are.
Differential Revision: https://phab.mercurial-scm.org/D10207
from __future__ import absolute_import
import hashlib
try:
from ..thirdparty import sha1dc # pytype: disable=import-error
sha1 = sha1dc.sha1
except (ImportError, AttributeError):
sha1 = hashlib.sha1