In screens that show a list of groups that a particular user is a member of, some users will see error popups or the groups simply won't load.
This is due to some JS that stores the username as an HTML attribute "data-user" and the way jQuery reads these.
We use $el.data('user'), which for most users returns something like "aahmed". For usernames that are all numbers, like 1234, this returns a number 1234. When the number starts with 0, the 0 is stripped.
Thus when we use that value anywhere, it's incorrect.
We should instead use $el.attr('data-user')