Incorrect exception message when same-name-sibling is prevented on import

When importing XML for a node with the same name as an existing node, but with different UUID, an ItemExistsException is thrown, effectively preventing the creation of a same-name sibling on import.

Assuming that same-name siblings are supposed to be prevented on import, that's totally perfect, but the error message of the Exception thrown is wrong and very misleading: "Node with the same UUID exists", where it should be something like "Node with same name exists, must prevent same-name-sibling".

https://github.com/apache/jackrabbit/blob/b23d6734381e49f236c3705820126803555608b5/jackrabbit-core/src/main/java/org/apache/jackrabbit/core/xml/SessionImporter.java#L381

As a suggestion, perhaps the code should further check for javax.jcr.nodetype.NodeDefinition#allowsSameNameSiblings before throwing the exception?