build: remove INRIA, NRL and MUSICA IPv6 quirks

Valar dohaeris.

Signed-off-by: David Lamparter <equinox@opensourcerouting.org>
Acked-by: Greg Troxel <gdt@ir.bbn.com>
Acked-by: Feng Lu <lu.feng@6wind.com>
Acked-by: Paul Jakma <paul@jakma.org>
diff --git a/bgpd/bgp_network.c b/bgpd/bgp_network.c
index c052744..cea430c 100644
--- a/bgpd/bgp_network.c
+++ b/bgpd/bgp_network.c
@@ -488,7 +488,7 @@
 }
 
 /* IPv6 supported version of BGP server socket setup.  */
-#if defined (HAVE_IPV6) && ! defined (NRL)
+#ifdef HAVE_IPV6
 int
 bgp_socket (unsigned short port, const char *address)
 {
@@ -588,7 +588,7 @@
     }
   return sock;
 }
-#endif /* HAVE_IPV6 && !NRL */
+#endif /* HAVE_IPV6 */
 
 void
 bgp_close (void)