htable: docs - rephrased info for db_expires to clarify its purpose

src/modules/htable/doc/htable_admin.xml

@@ -600,9 +600,16 @@ modparam("htable", "timer_interval", 10)
 	<section id="htable.p.db_expires">
 		<title><varname>db_expires</varname> (integer)</title>
 		<para>
-			If set to 1, the module will load/save the expires values of the items in
-			hash table from/to database. It applies only to hash tables that
-			have the auto-expires attribute defined.
+			If set to 1, the module loads/saves the value for expire of
+			the items in hash table from/to database. It applies only to hash
+			tables that have the auto-expires attribute defined. If set to 0,
+			only the key name and the value are loaded, the expires for each
+			item being set to 0.
+		</para>
+		<para>
+			Note that the module is not reloading automatically the items from
+			database when they expire, the reloading can be done only via RPC
+			command.
 		</para>
 		<para>
 		<emphasis>