After some updates we now get this message from bitbucket.
The database, as currently configured, is not accessible.
Fehler bei der Anmeldung f�r den Benutzer "jiradb,jdbc.password=xxxxxxx". ClientConnectionId:7122da01-f5b9-4a5a-9234-766604f3d62e
The user name looks wired to me :-) But i have no idea where this comes from. I've replaced the password by xxx. In the original message our db password was displayed.
Jira and Confluence are working fine.