Tidied socket reads/writes

src/server/xmppclient.c

@@ -24,6 +24,8 @@ xmppclient_new(struct sockaddr_in client_addr, int socket)
 void
 xmppclient_end_session(XMPPClient *client)
 {
+    while (recv(client->sock, NULL, 1, 0) > 0) {}
+    shutdown(client->sock, 2);
     close(client->sock);
 
     free(client->ip);