Copter: CIRCLE_OPTION make-mount-point-at-roi shouldn't apply during panorama shots

[rmackay9]

Feature Request

Copter's CIRCLE_OPTION parameter's "Make Mount ROI the center of the circle" option should probably not apply (e.g. mount shouldn't move) if the circle radius is 0 (e.g. doing a panorama shot) because this simply leads to the mount pointing straight down when most users would probably prefer the camera gimbal stay pointing however it was pointed (most likely horizontally).

We could argue that the user can always unselect the CIRCLE_OPTION before starting the circle but this is inconvenient if they're doing a collection or panorama and regular circle commands in Auto mode.

This was brought up in this discussion during AP-4.7.0-beta testing

Platform
[ ] All
[ ] AntennaTracker
[x ] Copter
[ ] Plane
[ ] Rover
[ ] Submarine