[6.0] be332215f Fix broken vsl-query example

[Dridi Boukelmoune]

commit be332215fb63ca7771e3b8626add4f7b2c8a68f3
Author: Dag Haavi Finstad <daghf at varnish-software.com>
Date:   Wed May 2 16:40:12 2018 +0200

    Fix broken vsl-query example

diff --git a/doc/sphinx/reference/vsl-query.rst b/doc/sphinx/reference/vsl-query.rst
index 891d36124..92b97c9e7 100644
--- a/doc/sphinx/reference/vsl-query.rst
+++ b/doc/sphinx/reference/vsl-query.rst
@@ -278,7 +278,7 @@ QUERY EXPRESSION EXAMPLES
 * Transaction group contains a request response status of 304, but
   where the request did not contain an if-modified-since header ::
 
-    ReqStatus == 304 and not ReqHeader:if-modified-since
+    RespStatus == 304 and not ReqHeader:if-modified-since
 
 * Transactions that have had backend failures or long delivery time on
   their ESI subrequests. (Assumes request grouping mode). ::