Release cyrus-sasl2 version 2.1.27+dfsg-1+deb10u1co2

Release https://gitlab.apertis.org/pkg/target/cyrus-sasl2/-/merge_requests/6:

• Drop the vendored BSD-4-Clause libdes when building
• Drop the unused BSD-4-Clause krb4 code when building
• copyright: Set the right overall license
• saslfinger: Drop due to problematic license
• copyright: Override license for BSD-4-Clause-UC files
• copyright: Add generated copyright file

and add two more commits:

• copyright: Stick overrides under debian/apertis
• copyright: Whitelist debian/