rtpengine: fix typo in docs

(cherry picked from commit 5cc888f0e9e305734621c0db1f63a47f2f0c381a)

src/modules/rtpengine/doc/rtpengine_admin.xml

@@ -2031,7 +2031,7 @@ modparam("rtpengine", "control_cmd_tos", 144)
 			The values not falling into the range <quote>0-1</quote> are ignored.
 		</para>
 		<example>
-		<title>Set <varname>control_cmd_tos</varname> parameter</title>
+		<title>Set <varname>hash_algo</varname> parameter</title>
 <programlisting format="linespecific">
 ...
 ### use SHA1 instead of legacy algorithm