Avoid show free-prive when buy course is not enabled

See #2483

main/template/default/session/sessions_current.tpl

@@ -25,10 +25,9 @@
                     </div>
                     <div class="block-info">
                         <i class="fa fa-user"></i> {{ session.users }} {{ "Users"|get_lang }}
-                        &nbsp;
-                        &nbsp;
                         <i class="fa fa-book"></i> {{ session.lessons }} {{ "Learnpaths"|get_lang }}
                     </div>
+                    {% if session.on_sale is defined %}
                         {% if session.on_sale != false %}
                             <div class="toolbar">
                                 <div class="buycourses-price">
@@ -46,6 +45,7 @@
                                 </div>
                             </div>
                         {% endif %}
+                    {% endif %}
                 </div>
 
             </div>