[master] a720dc820 improve cache_req_body doc wording

[Nils Goroll]

commit a720dc820d25458a3076b9e2869b1a7ee4020b52
Author: Nils Goroll <nils.goroll at uplex.de>
Date:   Tue Feb 26 18:48:36 2019 +0100

    improve cache_req_body doc wording

diff --git a/lib/libvmod_std/vmod.vcc b/lib/libvmod_std/vmod.vcc
index 39365af2a..a8468cfcf 100644
--- a/lib/libvmod_std/vmod.vcc
+++ b/lib/libvmod_std/vmod.vcc
@@ -299,11 +299,9 @@ $Function BOOL cache_req_body(BYTES size)
 Caches the request body if it is smaller than *size*.  Returns
 ``true`` if the body was cached, ``false`` otherwise.
 
-.. XXX fix wording: not the pass but rather the req body matters
-
-Normally the request body is not available after sending it to the
-backend.  By caching it is possible to retry pass operations,
-e.g. ``POST`` and ``PUT``.
+Normally the request body can only be sent once. Caching it enables
+retrying backend requests with a request body, as usually the case
+with ``POST`` and ``PUT``.
 
 Example::