Reported as bug 2526   Fix compile time errors - gnutsl deprecated functions
http://wald.intevation.org/tracker/index.php?func=detail&aid=2526&group_id=29&atid=220

diff -ru openvas-libraries-4.0.5.old/misc/network.c openvas-libraries-4.0.5/misc/network.c
--- openvas-libraries-4.0.5.old/misc/network.c	2011-07-30 22:07:44.000000000 +0200
+++ openvas-libraries-4.0.5/misc/network.c	2011-07-30 22:28:42.000000000 +0200
@@ -781,8 +781,10 @@
     }
 
   unblock_socket (fp->fd);
+
+  /* since gnutls 2.12.0 call to gnutls_transport_set_lowat is deprecated */
   /* for non-blocking sockets, gnutls requires a 0 lowat value */
-  gnutls_transport_set_lowat (fp->tls_session, 0);
+  /* gnutls_transport_set_lowat (fp->tls_session, 0); */
 
   gnutls_transport_set_ptr (fp->tls_session,
                             (gnutls_transport_ptr_t) GSIZE_TO_POINTER (fp->fd));