wifi: Always reset hotspot network label before updating

As the hotspot dialog is reused, we have to reset the connection label
everytime it’s shown. Otherwise obsolete informations shall be shown
if there isn't any active connection

panels/network/cc-wifi-hotspot-dialog.c

@@ -110,6 +110,8 @@ wifi_hotspot_dialog_update_main_label (CcWifiHotspotDialog *self)
 
   g_assert (CC_IS_WIFI_HOTSPOT_DIALOG (self));
 
+  gtk_label_set_markup (self->connection_label, "");
+
   if (!self->device)
     return;