When Spring Data REST is owning the home page it has its own
HandlerMapping with a fix (relatively) low priority. The /links
endpoint wants to own the home page as well, and our handler mapping
has a high priority for good reasons. This change addresses the
issue by checking if Spring Data REST is configured and if
the management context path (or  more specifically, the links
endpoint) is the same as the home page.

Fixes gh-3486