An error is displayed when leaving a page with a loading livedata

An error notification is displayed to the user when leaving a page with a loading livedata.
This gives a false sense of failure whereas this kind of error are not interesting to end users.

To reproduce:

• Visit a page with a livedata with a slow source (see https://myxwiki.org/xwiki/bin/view/WikiManager/ to see an example)
• While the loader is spinning, leave the page by clicking on a link

Expected:

• No notifications is displayed to the user

Actual:

• A error notification is displayed to the user, with the message "Updating the entries failed for an unknown reason."