[scope] CW-Husky USB blocked after power-up

[vrozic]

It often happens that CW-Husky USB communication gets block when running the first capture after power-up. This has already caused CI to break several times.

PR #300 provides a temporary solution. If the scope is initialised twice, the USB problem doesn't happen. I am not sure why this helps. I will have to look through CW API to root cause this problem and find a more reasonable fix.