[FIX] im_livechat: double click on :) => 1 message

Prevent sending multiple messages when multiple clicks on one feedback
icon.

opw-1863312
closes #26047

addons/im_livechat/static/src/js/im_livechat.js

@@ -3,6 +3,7 @@ odoo.define('im_livechat.im_livechat', function (require) {
 
 var local_storage = require('web.local_storage');
 var bus = require('bus.bus').bus;
+var concurrency = require('web.concurrency');
 var config = require('web.config');
 var core = require('web.core');
 var session = require('web.session');
@@ -304,6 +305,7 @@ var Feedback = Widget.extend({
         this.channel_uuid = channel_uuid;
         this.server_origin = session.origin;
         this.rating = undefined;
+        this.dp = new concurrency.DropPrevious();
     },
 
     on_click_smiley: function (ev) {
@@ -339,7 +341,7 @@ var Feedback = Widget.extend({
             rate: this.rating,
             reason : options.reason
         };
-        return session.rpc('/im_livechat/feedback', args).then(function () {
+        this.dp.add(session.rpc('/im_livechat/feedback', args)).then(function () {
             if (options.close) {
                 var content = _.str.sprintf(_t("Rating: :rating_%d"), self.rating);
                 if (options.reason) {