presence: added section for subs_remove_match parameter in docs

modules/presence/doc/presence_admin.xml

@@ -618,6 +618,28 @@ modparam("presence", "db_table_lock_type", 0)
 ...
 modparam("presence", "local_log_level", 3)
 ...
+</programlisting>
+	    </example>
+	</section>
+	<section id="presence.p.subs_remove_match">
+	    <title><varname>subs_remove_match</varname> (int)</title>
+	    <para>
+		Control how to match the subscriptions to remove from memory.
+		If set to 0, then the match is done on To-Tag (local generated),
+		if set to 1, then the match is done on all dialog attributes
+		(Call-Id, From-Tag, To-Tag).
+	    </para>
+	    <para>
+		<emphasis>
+		    Default value is 0.
+		</emphasis>
+	    </para>
+	    <example>
+		<title>Set <varname>subs_remove_match</varname> parameter</title>
+		<programlisting format="linespecific">
+...
+modparam("presence", "subs_remove_match", 1)
+...
 </programlisting>
 	    </example>
 	</section>