The error now in the openhab.log is:
2018-12-23 22:02:10.299 [ERROR] [sql.internal.MysqlPersistenceService] - mySQL: Failed connecting to the SQL database using: driverClass=com.mysql.jdbc.Driver, url=jdbc:mysql://192.168.8.10/OpenHAB, user=openhab
java.sql.SQLNonTransientConnectionException: CLIENT_PLUGIN_AUTH is required
at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:110) ~[230:org.openhab.persistence.mysql:1.13.0]
…
Hello!
New to this forum.
Just wanted to let anyone know that I successfully made the JDBC connection to work by the solution Kskaret suggested.
I downgraded the JDBC connector to version 5.1.39.
simply use bundle:uninstall in the karaf console (bundle:list will tell you the ID of the binding).
Moved the downloaded jar file to addons (/usr/share/openhab2/addons), restarted rpi and the service was up.