Fixed resolved discussion timeago not rendering

## What does this MR do?

Initialises the timeago element when a discussion is updated or resolved.

## Screenshots (if relevant)

![Screen_Shot_2016-11-22_at_11.49.22](/uploads/02900cc4de019ac33cd4d59d586629aa/Screen_Shot_2016-11-22_at_11.49.22.png)

## What are the relevant issue numbers?

Closes #24787

See merge request !7656