Possible infinite loop when serializing a Maven based InstalledExtension

This is not really easy to reproduce unless with wrong log that put extension as log parameter instead of extension id (which is how it's been found).

For some reason XStream enter in a pretty complex infinite loop when serializing an InstalledExtension instance of type created from a Maven object (the infinite look is probably more on the Maven model). It does not seems to be recursion issue since that would fail while here it's stuck for ever (or a very very long time at least).