Log Browser: scaling axis changes after "Set Scale to Default"

I've noticed that the scaling may not be set to the default when something is first graphed. It's not a big deal but it would be nice if it was consistent

To recreate the issue do this:

1. open a log file, ensure "Time" is not checked
2. log any item (e.g. ATT.Roll), note the scale of the bottom axis
3. right-mouse-button-click and "Set Scale to Default" and note the scale changes


Reproduce this in Mission Planner's Log Browser using the listed steps: open a log with Time unchecked, graph ATT.Roll, and record the bottom-axis scale before and after Set Scale to Default. Trace the Log Browser scaling behavior and ensure the initial scale matches the default-scale result, then repeat the steps to confirm the axis remains consistent.

Written by the indexing model from the issue text.