pyshark: upgrade for python3.6 support

BUG=chromium:1019337
TEST=CQ passes

Change-Id: I84673531f38561bc8b712e362dfac2f1b048b9d2
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/overlays/portage-stable/+/2049185
Commit-Queue: Brian Norris <briannorris@chromium.org>
Reviewed-by: Brian Norris <briannorris@chromium.org>
Tested-by: Brian Norris <briannorris@chromium.org>
4 files changed