Prevention of validation error "schemaName is not allowed on oracle"

Trigger functions do not work with Liquibase 3.1 and Liquibase-Oracle 3.0. createTrigger (also disableTrigger, renameTrigger and enableTrigger) do not work and give the validation error "schemaName is not allowed on oracle".

This is caused by the initialization of the schemaName member with the default database schema, if no schema name was provided in the XML. In my opinion, this can never work.