Since this is an admin screen, we can show the exception message
unconditionally.

Fix that persistent would override other database options.

Closes: #1546

Remove references to defaultDictionary

Cleanup hooks

Hook 'metadata_hosted' and 'frontpage' are no longer called so do
not register hooks for them. Update the docs. Remove useless call
to configpage hook on admin module Test page (likely a copy-paste
error).

This was already the result after processing previously.