The current codebase has removed the childDropChanges attribute. Are you
able to do a local build where you remove the attribute and
keep childDropChanges as a local variable in generateStatements?
You
can see the current code for reference at
https://github.com/liquibase/liquibase/blob/master/liquibase-core/src/main/java/liquibase/change/core/DropAllForeignKeyConstraintsChange.java
I'm
not currently planning on an official 2.0.x update.
Nathan