Course url is now hidden by default

ui/gui-course.ui

@@ -74,7 +74,7 @@
                 <child>
                   <object class="GtkLinkButton" id="url">
                     <style><class name="url"/></style>
-                    <property name="visible">True</property>
+                    <property name="visible">False</property>
                     <property name="opacity">0.4</property>
                     <property name="label" translatable="no">https://…</property>
                     <!--<property name="margin_top">3</property>-->
@@ -134,3 +134,4 @@
 </interface>
 
 
+