problem changing negative servo.gain

[johnm]

Finally working at getting tinypilot working again.
Seems like the new software changed the motor direction.
Last year had servo gain of 2 and it reverted to  1.
Via the opencpn plugin changed to -1 forgetting that I needed -2.
That fixed the motor direction.
With servo.gain at -1 it did not allow changing via opencpn plug in.
If I edited pypilot.conf it always reverted back..
Even tried changing via a program.
If I changed to 1 then it allowed me to set to -2.
Something is not allowing to change servo.gain if it's -1.