client: Prepare to work with a list of servers

There is no VTY code yet and no servers in the list but it looks
good client this.

Change-Id: Ic35748f1a95a880a9fa49dd18361592d8ac941ba
diff --git a/src/osmo_client_main.c b/src/osmo_client_main.c
index 694470e..0d48e1b 100644
--- a/src/osmo_client_main.c
+++ b/src/osmo_client_main.c
@@ -222,6 +222,7 @@
 	vty_client_init(pcap_client);
 
 	/* initialize the queue */
+	INIT_LLIST_HEAD(&pcap_client->conns);
 	pcap_client->conn.client = pcap_client;
 	osmo_wqueue_init(&pcap_client->conn.wqueue, 10);
 	pcap_client->conn.wqueue.bfd.fd = -1;