Rules list page is loaded twice

[frantz45]

1. Click on Wizard / Alert rules
2. List of rules is loaded
3. 3-4 seconds later the list is loaded again

This behavior is not systematic but it happens very often.

In the browser developer console we can see 2 API requests.
The developer console complains because both requests are slow (around 750ms which is >500ms).
It may be a performance issue because I have many rules (>200).
Maybe we should paginate rules (50 rules per page ?)