This got me for a couple of things, but it's just a matter of retraining it - I think (as a user, not developer of LB, this is my mental model of it!)
If you type 'go' then hunt down for 'google search' before pressing space, it reinforces that 'google search' is the best response to 'go'. After a couple of times, this will be your default.
Alternately, you can hunt down 'google search' then press CMD+ALT+A to assign it an abbreviation ("go"?)
Make sure you use the 'Google (Built-in action)' version (or better still, 'DuckDuckGo (Built-in action)').