fix: do not try to reset tooltip of feature not on map

This can happen in a situation where:
- a layer as zoom limits
- we click on a feature, which opens a popup
- then zoom over the layer's limit (with
  scroll or keyboard, not keyboard, in order to not close the popup)
- then click in anywhere in the map, which will close the popup

Since the highlight of features on click (cf #1359), we redraw them
on popupclose, which explains the bug described above.

fix #1575

umap/static/umap/js/umap.features.js

@@ -794,8 +794,10 @@ L.U.PathMixin = {
   },
 
   _redraw: function () {
+    if (this.datalayer && this.datalayer.isVisible()) {
       this.setStyle()
       this.resetTooltip()
+    }
   },
 
   onAdd: function (map) {