add compute_t_prim for method=PIMD

src/REPLICA/fix_pimd_langevin.cpp

@@ -696,6 +696,7 @@ void FixPIMDLangevin::post_force(int /*flag*/)
     inter_replica_comm(x);
     spring_force();
     compute_spring_energy();
+    compute_t_prim();
     if (mapflag) {
       for (int i = 0; i < nlocal; i++) { domain->unmap_inv(x[i], image[i]); }
     }