ergoCub: lower pitch and roll head PID gains to avoid overshoot

[mfussi66]

This PR changes the gains of the pitch and roll position PIDs of the ergoCub head. The gains were found by the automated robust procedure, with the following requirements:

sampling_time = 1e-3;         % sec
responsetime = 0.4; 			% sec
dcerror = 0.1;      				% perc
peakerror = 1.05;    			% fract relative
peak_disturbance = 0.1;      % abs deg
tSettle_disturbance = 0.2;   % sec
maxOvershoot = 5;  			% perc

which, compared to before, is a reduction in overshoot from 10% to 5% and a peak error from 1.1 to 1.05.

It results in the following plot:

And the related video:

VID_20230130_195722_961.mp4