bug#25274: Fix bug in customizing `mail-sources' variable

[Bake Timmons]

>From b51b93c8b1e9a57564e750894eaa35781e496fe5 Mon Sep 17 00:00:00 2001
From: Bake Timmons <b2timmons@speedymail.org>
Date: Sun, 25 Dec 2016 22:03:13 -0500
Subject: [PATCH] Fix bug in customizing `mail-sources' variable

* lisp/gnus/mail-source.el (mail-sources): Use list instead of cons
for lone argument.
---
 lisp/gnus/mail-source.el | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lisp/gnus/mail-source.el b/lisp/gnus/mail-source.el
index 59a97dbb8c..8b7c8e0847 100644
--- a/lisp/gnus/mail-source.el
+++ b/lisp/gnus/mail-source.el
@@ -66,7 +66,7 @@ See Info node `(gnus)Mail Source Specifiers'."
          (repeat :tag "List"
           (choice :format "%[Value Menu%] %v"
                   :value (file)
-                  (cons :tag "Group parameter `mail-source'"
+                  (list :tag "Group parameter `mail-source'"
                         (const :format "" group))
                   (cons :tag "Spool file"
                         (const :format "" file)
-- 
2.11.0