The error that I get on phpMyAdmin is the following
The phpMyAdmin configuration storage is not completely configured, some extended features have been deact
The presence of the logout button depends on whether you are required to login or not, in the first place. This is tweakable in PHPMyAdmin config files.
Yet, I don't think that would change anything concerning your error message. You would need to fix the configuration for the message to go away.
Edit: this is the kind of solution you should be searching for. And here are plenty of others for you to explore ^^