How do I clear the server list on the initial addons page ?

When I open Add-ons it shows mezzmo (the addon) and when I open that the servers. but
There are a couple of issues for me here.
1. every time I do this it searches - and finds a server which is says isnt responding. (with an IP address that doesnt actually exist on my next work - something like 1.2.3.4:55000 where 4 is the device - and there is not device at that address
2. I added a server manually - so now I have the same server twice.

Thanks