Dashboard generates iframes to fit grid, populates with dud API Call

[quadrophobiac]

If more panels than chosen metrics populate a dashboard Bothan autofills iframes with this endpoint
/metrics/-- Select a metric--/*/*?$params
this hasn't been detected so far as the iframes are populated with black text on black background but the iframe contains a header of Internal Server Error

[quadrophobiac]

will add picture soon

[quadrophobiac]

Steps to Reproduce (for problems)

Provide a link to a live example, or an unambiguous set of steps to reproduce this bug. Include code to reproduce, if relevant

1. Go to edit dashboard
2. Set grid to 2 * 2 or 3 * 3
3. only select visualisations for half (max) of the tiles available
4. save

when you view your dashboard you should see something similar to https://demo.bothan.io/dashboards/bothan or the image below