+ * @param error_cb function to call on error (i.e. disconnect); note that
+ * unlike the other error callbacks in this API, a call to this
+ * function does NOT destroy the monitor handle, it merely signals
+ * that monitoring is down. You need to still explicitly call
+ * #GNUNET_NAMESTORE_zone_monitor_stop().
+ * @param error_cb_cls closure for @a error_cb