Revert "Remove more gnutls references."

This reverts commit 6a25507e90.

README.FIRST

@@ -27,7 +27,8 @@ Necessary Requirements:
 Feature Specific Requirements:
 
 - For SSL Clients, SSL Challenge controlled OPER feature, and encrypted server links,
-  a working OpenSSL library.
+  a working OpenSSL library or GnuTLS library.  CHALLENGE is not supported on GnuTLS
+  yet.
 
 - For encrypted oper and (optional) server passwords, a working DES, MD5, or SHA library
   implementing crypt().

libratbox/include/arc4random.h

@@ -1,6 +1,6 @@
 
 
-#if !defined(HAVE_OPENSSL) && !defined(HAVE_ARC4RANDOM)
+#if !defined(HAVE_OPENSSL) && !defined(HAVE_GNUTLS) && !defined(HAVE_ARC4RANDOM)
 void arc4random_stir(void);
 uint32_t arc4random(void);
 void arc4random_addrandom(uint8_t *dat, int datlen);

libratbox/src/arc4random.c

@@ -31,7 +31,7 @@
 #include <libratbox_config.h>
 #include <ratbox_lib.h>
 
-#if !defined(HAVE_OPENSSL) && !defined(HAVE_ARC4RANDOM)
+#if !defined(HAVE_OPENSSL) && !defined(HAVE_GNUTLS) && !defined(HAVE_ARC4RANDOM)
 
 #include "arc4random.h"