PyDARM 0.0.3: Bug in calcs.py -- Too weak of check for what stages of actuation are used

IF the actuation configuration is only partial filled for one arm -- BUT that n-th arm is "turned off" with either the darm_output_matrix or darm_feedback_n parameters, -- the gds_actuation_correction method in CALCSModel class in the calcs.py module incorrectly still tries to compute the n-th arm, and barfs.

Temporary fix is to delete (or comment out) all information from the arm section (e.g. [actuation_y_arm]) you don't want.