recv_packet: fix reported packet size on abnormal payloads

src/main.c

@@ -150,6 +150,7 @@ int recv_packet(int sockfd, rcon_packet_t *packet) {
         }
         packet->body[body_size] = '\0';
     } else {
+        packet->size = sizeof(int32_t) * 2 + 2;
         packet->body[0] = '\0';
     }