Enable GNU TLS by default.

* am/tls.m4: Use --without-gnutls instead of --with-gnutls.

@@ -142,10 +142,10 @@ mailutils-specific configuration options:
 
 	Build 'mail' without readline support.
 
-    --with-gnutls
+    --without-gnutls
 
-	Enable the TLS/SSL server-side encryption via GnuTLS
-	(a Transport Layer Security Library) in IMAP4/POP3 daemons.
+	Disable the TLS/SSL encryption via GnuTLS (a Transport Layer
+	Security Library) in IMAP4/POP3 daemons and utilities.
 
     --with-gsasl
 

 dnl This file is part of GNU mailutils.
-dnl Copyright (C) 2003, 2007 Free Software Foundation, Inc.
+dnl Copyright (C) 2003, 2007, 2009 Free Software Foundation, Inc.
 dnl
 dnl GNU Mailutils is free software; you can redistribute it and/or modify
 dnl it under the terms of the GNU General Public License as published by
@@ -20,10 +20,10 @@ AC_DEFUN([MU_CHECK_TLS],
  if test "x$WITH_GNUTLS" = x; then
    cached=""
    AC_ARG_WITH([gnutls],
-               AC_HELP_STRING([--with-gnutls],
-                              [use GNU TLS library]),
+               AC_HELP_STRING([--without-gnutls],
+                              [do not use GNU TLS library]),
                [WITH_GNUTLS=$withval],
-               [WITH_GNUTLS=no])
+               [WITH_GNUTLS=yes])
 
    if test "$WITH_GNUTLS" != "no"; then
      AC_CHECK_HEADER(gnutls/gnutls.h,