Fixed Updating a moderator does not set is_moderator = 1 in xf_user

[Rigel Kentaurus]

I got a bunch of moderators setup already from my import process from vBulletin

However, none of those had is_moderator set to 1 (I noticed they did not appear in the Staff Online sidebar)
When I update their moderator permissions through ACP, the flag is not set. I had to delete the permissions and re-add them for that flag to be set.

 

[Mike]

I'm not actually sure why this happened in the first place (it's something I want to investigate), but I have changed this anyway - little harm in it.