textops: docs - proper example for append_body_part() with headers

src/modules/textops/doc/textops_admin.xml

@@ -1725,8 +1725,8 @@ Content-Disposition: signal;handling=required
 		<title><function>append_body_part</function> with headers</title>
 		<programlisting format="linespecific">
 ...
-$var(b) = "<info>active</info>";
-append_body_part("$var(b)", "application/xml\r\nX-Header: xyz");
+$var(b) = "7e Od 04 55 75 69 20 4d 61 6b 65 43 61 6c 6c";
+append_body_part("$var(b)", "application/vnd.cirpack.isdn-ext\r\nX-Header: xyz", "signal;handling=required");
 msg_apply_changes();
 ...
 
@@ -1734,6 +1734,7 @@ msg_apply_changes();
 
 ...
 Content-Type: application/vnd.cirpack.isdn-ext
+X-Header: xyz
 Content-Disposition: signal;handling=required
 
 7e Od 04 55 75 69 20 4d 61 6b 65 43 61 6c 6c