Caused by the fact, that schema file for 2.1.0 is missing:

tigase@ip-10-0-40-121:~/tigase-server$ ls -lah database/mysql-message-archiving-*
-rw-r--r-- 1 tigase tigase 26K Jul 11 09:34 database/mysql-message-archiving-2.0.0.sql

We agreed that it must be present, but now I'm not sure nor remember reasoning. After pondering it some more it I'm fairly sure it was intended as a failsafe mechanism - we only store version from the files that were correctly loaded. Closing.