fix_dplr.cpp set atom->image when pre_force (#3345)

The atom->image of the wannier centroid should be set to the same as its
real counterpart when assigning the position.

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Co-authored-by: Yifan Li李一帆 <yifanl0716@gmail.com>
(cherry picked from commit b1de9e6)

source/lmp/fix_dplr.cpp

@@ -522,6 +522,7 @@ void FixDPLR::pre_force(int vflag) {
     // int res_idx = sort_fwd_map[sel_fwd[idx0]];
     int res_idx = sel_fwd[idx0];
     // int ret_idx = dpl_bwd[res_idx];
+    atom->image[idx1] = atom->image[idx0];
     for (int dd = 0; dd < 3; ++dd) {
       x[idx1][dd] =
           x[idx0][dd] + tensor[res_idx * 3 + dd] * dist_unit_cvt_factor;