Fix T99979: GPencil strokes cannot be edited after set origin

The stroke points were changed but the bounding box calculation was not done and this produced a problem in any bounding box check done by different tools.

source/blender/editors/object/object_transform.cc

@@ -1598,6 +1598,7 @@ static int object_origin_set_exec(bContext *C, wmOperator *op)
                     }
                   }
                 }
+                BKE_gpencil_stroke_geometry_update(gpd, gps);
               }
             }
           }