Add missing comma to wsgiref doc (GH-9932)

diff --git a/Doc/library/wsgiref.rst b/Doc/library/wsgiref.rst
index f8811c5..e0f745f 100644
--- a/Doc/library/wsgiref.rst
+++ b/Doc/library/wsgiref.rst
@@ -54,7 +54,7 @@
 
    This function is useful when creating a gateway that wraps CGI or a CGI-like
    protocol such as FastCGI.  Typically, servers providing such protocols will
-   include a ``HTTPS`` variable with a value of "1" "yes", or "on" when a request
+   include a ``HTTPS`` variable with a value of "1", "yes", or "on" when a request
    is received via SSL.  So, this function returns "https" if such a value is
    found, and "http" otherwise.