*: fix in_addr initialisers

Signed-off-by: David Lamparter <equinox@opensourcerouting.org>
diff --git a/bgpd/bgp_attr.c b/bgpd/bgp_attr.c
index 5c832ed..3f09103 100644
--- a/bgpd/bgp_attr.c
+++ b/bgpd/bgp_attr.c
@@ -1804,7 +1804,7 @@
   /* same goes for as4_aggregator */
   struct aspath *as4_path = NULL;
   as_t as4_aggregator = 0;
-  struct in_addr as4_aggregator_addr = { 0 };
+  struct in_addr as4_aggregator_addr = { .s_addr = 0 };
 
   /* Initialize bitmap. */
   memset (seen, 0, BGP_ATTR_BITMAP_SIZE);