Dangerous bug in parameter compare. (current params misrepresented)

#### Issue details
The parameter's current value can be displayed as "zero" instead of the real value.

This is dangerous if one is to believe something was not set, and toggles it - or somebody takes note of "current" value, and later enter it to "restore" the change.

example: check the ATC_RAT_PIT_P ?


#### Version
1.3.77

#### Platform
[ x] All
[ ] AntennaTracker
[ ] Copter
[ ] Plane
[ ] Rover
[ ] Sub

#### Airframe type
n/a

#### Hardware type
n/a

#### Logs
the screenshot says all, logs do not contain anything about this.

Begin by reproducing the parameter comparison for ATC_RAT_PIT_P on Mission Planner 1.3.77 and trace the UI path that renders the current value; the issue names no source file or test. Done means the displayed current value matches the actual parameter, including this example, with a regression check if the relevant test location can be found.

Written by the indexing model from the issue text.