Main wiki's breadcrumb doesn't display subwikis

The subwiki breadcrumb also displays wikis, while the main wiki doesn't. This was tested locally with the Admin user.

I would have expected:

• both breadcrumbs to display wikis (if subwikis exist for the instance)
• or the reverse behavior: the subwiki to display a localized breadcrumb, while the main wiki to display the global view (including subwikis) - I guess it also depends on the rights of the user.

Breadcrumb should the most reliable when displaying the navigation, and the main wiki is the central hub, so that's why I reported this as a bug.