minor #5188 Updated Cookies & Caching section (lukey78)

This PR was submitted for the 2.6 branch but it was merged into the 2.3 branch instead (closes #5188).

Discussion
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Updated Cookies & Caching section

Correct code for Varnish 4 (unset instead of remove)

Commits
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805a548 Updated Cookies & Caching section

Author: xabbuh

cookbook/cache/varnish.rst

@@ -75,23 +75,44 @@ session cookie, if there is one, and get rid of all other cookies so that pages
 are cached if there is no active session. Unless you changed the default
 configuration of PHP, your session cookie has the name ``PHPSESSID``:
 
-.. code-block:: varnish4
+.. configuration-block::
 
-    sub vcl_recv {
-        // Remove all cookies except the session ID.
-        if (req.http.Cookie) {
-            set req.http.Cookie = ";" + req.http.Cookie;
-            set req.http.Cookie = regsuball(req.http.Cookie, "; +", ";");
-            set req.http.Cookie = regsuball(req.http.Cookie, ";(PHPSESSID)=", "; \1=");
-            set req.http.Cookie = regsuball(req.http.Cookie, ";[^ ][^;]*", "");
-            set req.http.Cookie = regsuball(req.http.Cookie, "^[; ]+|[; ]+$", "");
-
-            if (req.http.Cookie == "") {
-                // If there are no more cookies, remove the header to get page cached.
-                remove req.http.Cookie;
+    .. code-block:: varnish4
+
+        sub vcl_recv {
+            // Remove all cookies except the session ID.
+            if (req.http.Cookie) {
+                set req.http.Cookie = ";" + req.http.Cookie;
+                set req.http.Cookie = regsuball(req.http.Cookie, "; +", ";");
+                set req.http.Cookie = regsuball(req.http.Cookie, ";(PHPSESSID)=", "; \1=");
+                set req.http.Cookie = regsuball(req.http.Cookie, ";[^ ][^;]*", "");
+                set req.http.Cookie = regsuball(req.http.Cookie, "^[; ]+|[; ]+$", "");
+    
+                if (req.http.Cookie == "") {
+                    // If there are no more cookies, remove the header to get page cached.
+                    unset req.http.Cookie;
+                }
             }
         }
-    }
+
+    .. code-block:: varnish3
+
+        sub vcl_recv {
+            // Remove all cookies except the session ID.
+            if (req.http.Cookie) {
+                set req.http.Cookie = ";" + req.http.Cookie;
+                set req.http.Cookie = regsuball(req.http.Cookie, "; +", ";");
+                set req.http.Cookie = regsuball(req.http.Cookie, ";(PHPSESSID)=", "; \1=");
+                set req.http.Cookie = regsuball(req.http.Cookie, ";[^ ][^;]*", "");
+                set req.http.Cookie = regsuball(req.http.Cookie, "^[; ]+|[; ]+$", "");
+    
+                if (req.http.Cookie == "") {
+                    // If there are no more cookies, remove the header to get page cached.
+                    remove req.http.Cookie;
+                }
+            }
+        }
+    
 
 .. tip::