[FIX] portal: Remove non compliant ES5 syntax

Currently Odoo JavaScript code base support only ecmascript <= 5

So using a non compliant ES5 syntax can trigger a javascript engines
crash for some browsers like: IE, webview used by some old mobile
devices.

This commit fixes non compliant JS code syntax found to avoid potential
crash.

closes odoo/odoo#31522

Signed-off-by: VincentSchippefilt <VincentSchippefilt@users.noreply.github.com>

addons/portal/static/src/js/portal_chatter.js

@@ -102,7 +102,7 @@ var PortalChatter = Widget.extend({
                 route: '/mail/chatter_init',
                 params: this._messageFetchPrepareParams()
             }),
-            this._super.apply(this, arguments),
+            this._super.apply(this, arguments)
         ).then(function(result){
             self.result = result;
             self.options = _.extend(self.options, self.result['options'] || {});