[server] Use CryptContext's hash method instead of deprecated encrypt method
Getting rid of the following deprecation warning:
::
the method passlib.context.CryptContext.encrypt() is deprecated as of
Passlib 1.7, and will be removed in Passlib 2.0, use CryptContext.hash()
instead.
[cwctl] on upgrade, clear instance_md5_version cache
The generate-static-datadir depends on a correct
config.instance_md5_version(), and we just invalidated it by
upgrading the instance.