external: Sync with openconnect rev c69636e96

Signed-off-by: Kevin Cernekee <cernekee@gmail.com>
libs/assets: Sync with latest sources

Signed-off-by: Kevin Cernekee <cernekee@gmail.com>
AuthFormHandler: Fix saved authgroup logic

Select the saved authgroup, not the server default authgroup.  Log a
warning if the saved authgroup isn't listed in the dropdown.

Signed-off-by: Kevin Cernekee <cernekee@gmail.com>
AuthFormHandler: Prevent batch mode from "running away"

If the server sends the same exact auth form twice, assume there is a
problem with the cached data and revert back to prompting the user (where
allowed) or aborting the connection attempt.

Signed-off-by: Kevin Cernekee <cernekee@gmail.com>