/camp bug report

Logout commands such as /camp and /exit trigger addon warning popup.
This is a side effect with addons' SlashCmdList global variable implementation.

Reproduction steps :
* Disable/uninstall all addons
* Install the DoNothing test case addon from here : https://lenwe.info/collab/blizzard/DoNothing.zip
* Log in any character
* Wait for 10 seconds
* Type /camp => Error message shows up
* Type /camp again => Character successfully logs out