SummationByPart assumes `cctk_lsh == cctk_ash`

[Roland Haas]

SummationByParts sets ni = cctk_lsh[0] but then uses this (in Fortran code) to size the array in memory:

CCTK_REAL, dimension(ni,nj,nk), intent(IN) :: var

which will fail when cctk_lsh != cctk_ash that is when padding is used.