Improve LinOTP migration script
Improve LinOTP migration script

* Work with privacyIDEA 3.x
* Use a config file for migration
* Allow setting new arbitrary tokeninfo
* Allow reencrypting the token secrets

privacyidea/privacyidea,privacyidea/privacyidea,privacyidea/privacyidea,privacyidea/privacyidea,privacyidea/privacyidea,privacyidea/privacyidea