Bug in FixMesh Destructor

At the line
https://github.com/CFDEMproject/LIGGGHTS-PUBLIC/blob/3.5.0/src/fix_mesh....
if (element_exclusion_list_ && 0 == comm->me)
the fix destructor is referencing the comm class, which is not only pointless (the FILE pointer can be non-zero only on proc 0), but also produces undefined behaviour since the comm class is already destroyed at this point ( see https://github.com/CFDEMproject/LIGGGHTS-PUBLIC/blob/3.5.0/src/lammps.cp... ).
In addition to removing the ceck 0 == comm->me, I recommend setting the pointers to 0, immediately after deletion in LAMMPS::destroy().

Cheers
Daniel