Fix gimbalResponseSpeed in ModuleGimbal

[lamont-granquist]

See description of the problem in the ModuleGimbal implementation here:

MuMech/MechJeb2#1859

The problem is that fixing this issue will likely mean increased response time delays, which may impact playability at the keyboard, and will likely make all PID controllers, including stock SAS even worse.

If this is fixed, it should probably be hidden behind a toggle and not enabled by default until PIDs/SAS can get stabilized. It also should probably bake in RO before being pushed to everyone in KCF.