Google Search sometimes tries to index non-existent Javadoc reference files

[dmitrykuzmin]

We received a (5xx) server error in Google Search Console for a request targeting a non-existent Javadoc file:

This most probably means that the Google Search Engine tried to index this file, although our docs no longer reside under /javadoc and are in general organised differently from before.

This doesn't seem like a major issue, but should still probably be looked into.

Indexing for the current Spine version appears to work OK: