`retry import` does not work when import has been suspended

When an import has been suspended due to too many failures, you can still see a button/link with the label "Try again".

Clicking on it does seemingly nothing.

The import has to be enabled by an admin first.

Instead of showing the button/link, a better way would be to show a message that the user should contact the Launchpad support.

The button/link or even the whole form misses a check whether the import has been suspended:
https://git.launchpad.net/launchpad/tree/lib/lp/code/templates/import-details.pt#n19

( something like: condition="code_import/review_status/enumvalue:FAILING" ).