Show error message when there's no author assigned on campaign edit

[ctrance]

I edited the campaign then removed the only author for the campaign. Upon saving, I didn't get an error message.

[jshslsky]

If you performed this action as an admin, I think this is OK to allow. The adage about admins is "with great power comes great responsibility."

[ctrance]

@joshuaselsky - I got the same behavior if I'm editing the campaign as non-admin.

[jshslsky]

OK, I just talked to @hongsudt and we agreed to just classify this as low priority.