audio/festival: unbreak build with Clang 6 (C++14 by default)

sig2fv_main.cc:190:18: error: invalid suffix on literal; C++11 requires a space between literal and identifier [-Wreserved-user-defined-literal]

"    default: "DEFAULT_WINDOW"\n\n"
               ^

server.cc:125:68: error: invalid operands to binary expression ('__bind<int &, sockaddr *, unsigned

  long>' and 'int')
if (bind(fd, (struct sockaddr *)&serv_addr, sizeof(serv_addr)) != 0)
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ^  ~

Reported by: antoine (via bug 224669)