[IMP] web: multi-click on save on view form (no fp)

When clicking on save several time when editing a view form it can be
saved several times which can be an issue for one to many.

The normal happenstance when saving should be as follow:

-> save (click)
-> wait write result
-> received write result
-> reload the form with updated data and updates buttons

But when clicking several time, it could become:

-> save (click)
-> wait write result
-> received write result
-> save (click)
-> wait write result
-> received write result
-> reload the form with updated data and updates buttons

This commit only reinstate the saving feature once the form is reloaded.

related to opw-671793
backport of 8.0's dd714ac

note: no need to forward-port

addons/web/static/src/js/view_form.js

@@ -726,14 +726,16 @@ instance.web.FormView = instance.web.View.extend(instance.web.form.FieldManagerM
         $(e.target).attr("disabled", true);
         return this.save().done(function(result) {
             self.trigger("save", result);
-            self.reload().then(function() {
+            self.reload().always(function(){
+                $(e.target).attr("disabled", false);
+            }).then(function() {
                 self.to_view_mode();
                 var parent = self.ViewManager.ActionManager.getParent();
                 if(parent){
                     parent.menu.do_reload_needaction();
                 }
             });
-        }).always(function(){
+        }).fail(function(){
             $(e.target).attr("disabled", false);
         });
     },