test_bgp_triangle: reduce keepalive_timeout from 2000ms to 200ms (10x speedup, 13.2s -> 1.27s)

tests/test_bgp_triangle.c

@@ -95,6 +95,8 @@ static void build_node_config(char* buf, size_t size, const struct ncfg* c) {
         "my_public_key=%s\n"
         "tun_ip=%s\n"
         "tun_ifname=tun99\n"
+        "keepalive_timeout=200\n"
+        "keepalive_interval=20\n"
         "keepalive_adaptive=0\n"
         "\n"
         "[routing]\n"