Typo for calculating multisphere moment of inertia tensor

In fix_template_multisphere.cpp line 428 there is a typo causing incorrect calculated moment of inertia tensors using the Monte-Carlo integration method:

moi_[2][1] = (moi_[2][1]+moi_[2][0])/2.;

should be corrected to:

moi_[2][1] = (moi_[2][1]+moi_[1][2])/2.;

https://github.com/CFDEMproject/LIGGGHTS-PUBLIC/blob/master/src/fix_temp...