Update to new offlineimap (7.3.3) problem

[Dieter Faulbaum]

Today the offlineimap3 on Debian bullseye offers the new (python3 
based)
version 0.0~git20210105.00d395b+dfsg-1.

After installing it, I get a problem with my local IMAP server, 
which works well with version 7.3.2:
ERROR: Unknown SSL protocol connecting to host 'frangula' for 
repository 'Local-IN-Berlin'. OpenSSL responded:
[SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed: self 
signed certificate (_ssl.c:1123)

The 'relevant' part in the config file for this host is:
[general]
...
sslcacertfile = /etc/ssl/certs/ca-certificates.crt

[Repository Local]
type = IMAP
remotehost = <hostname>
remoteuser = <user>
remotepass = <password>
cert_fingerprint = 
c1:bc:d0:94:3d:19:66:c9:93:ec:44:cb:eb:26:d3:40:c1:4b:32:d2


Any idea what I cant do against this error?

Thanks for any help

Dieter