Fix data_objects/display_piv.py set_data

Author: paugier

src/fluidimage/data_objects/display_piv.py

@@ -319,7 +319,7 @@ def select_arrow(self, ind, artist=None):
             deltay = result.deltays_wrong[ind_all]
 
         self._point.set_visible(True)
-        self._point.set_data(ix, iy)
+        self._point.set_data([ix], [iy])
 
         text = (
             f"vector {ind_all} at ix = {ix} : iy = {iy}"