Notice: Undefined index: token in drupalchat_user_logout()

Every time a user logs out, a new notice is added in DB Log:

Notice: Undefined index: token in drupalchat_user_logout()

I've tracked down the issue and found that there is a code block on drupalchat_user_logout(), which meant to delete the commercial iFlyChat session token. This code block should have to be placed in the if-statement just above it, which explicitly checks if the site is using the commercial iFlyChat.

I've created a patch moving this code block into the if-statement.

Please review the patch.