[FIX] web_planner: untranslated planner

Missing context in call to render the planner leading to untranslated planner.
Use the session to get the user context as outside of the view manager.

opw 660627

addons/web_planner/static/src/js/web_planner_common.js

@@ -5,6 +5,7 @@ var core = require('web.core');
 var Dialog = require('web.Dialog');
 var Model = require('web.Model');
 var Widget = require('web.Widget');
+var session = require('web.session');
 var utils = require('web.utils');
 
 var QWeb = core.qweb;
@@ -65,7 +66,9 @@ var PlannerDialog = Widget.extend({
     willStart: function() {
         var self = this;
         var res = this._super.apply(this, arguments).then(function() {
-            return (new Model('web.planner')).call('render', [self.planner.view_id[0], self.planner.planner_application]);
+            return (new Model('web.planner')).call('render',
+                [self.planner.view_id[0], self.planner.planner_application],
+                {context: session.user_context});
         }).then(function(template) {
             self.$res = $(template);
         });