[master] f72a7e0 document a possible pitfall with the probe .request attribute

[Nils Goroll]

commit f72a7e0dd010277134fea5fbbacad5821ad50054
Author: Nils Goroll <nils.goroll at uplex.de>
Date:   Wed Jan 17 19:15:12 2018 +0100

    document a possible pitfall with the probe .request attribute

diff --git a/doc/sphinx/reference/vcl.rst b/doc/sphinx/reference/vcl.rst
index 024b568..1d04884 100644
--- a/doc/sphinx/reference/vcl.rst
+++ b/doc/sphinx/reference/vcl.rst
@@ -274,9 +274,14 @@ There are no mandatory options. These are the options you can set:
 
   ``.request``
     Specify a full HTTP request using multiple strings. ``.request`` will
-    have ``\r\n`` automatically inserted after every string. 
+    have ``\r\n`` automatically inserted after every string.
     Mutually exclusive with ``.url``.
 
+    *Note* that probes require the backend to complete sending the
+    response and close the connection within the specified timeout, so
+    ``.request`` will, for ``HTTP/1.1``, most likely need to contain a
+    ``"Connection: close"`` string.
+
   ``.expected_response``
     The expected HTTP response code. Defaults to ``200``.