Illegal reflective access by com.createsend.util.ErrorDeserialiser

[mdewilde]

We see following warning using createsend-java 7 on Java 11:

WARNING: An illegal reflective access operation has occurred
WARNING: Illegal reflective access by com.createsend.util.ErrorDeserialiser (jar:file:/app.jar!/BOOT-INF/lib/createsend-java-7.0.0.jar!/) to field sun.reflect.generics.reflectiveObjects.ParameterizedTypeImpl.actualTypeArguments
WARNING: Please consider reporting this to the maintainers of com.createsend.util.ErrorDeserialiser
WARNING: Use --illegal-access=warn to enable warnings of further illegal reflective access operations
WARNING: All illegal access operations will be denied in a future release