MariaRocks port: "get rid of Invalid (old?) table or database name" error

Running MTR tests produces an error like this after the test run:

... 140562896741120 [ERROR] Invalid (old?) table or database name '.rocksdb'

There seems to be no way to have the MariaRocks to prevent these, so
the current way to fix them is to have --ignore-db-dirs in my.cnf

storage/rocksdb/mysql-test/rocksdb/suite.opt

+--ignore-db-dirs=.rocksdb