message: Remove the useless parameters of postgresql metaData()
diff: @@ -70,8 +70,7 @@ ZEND_BEGIN_ARG_INFO_EX(arginfo_pg_num_rows, 0, 0, 0)
  ZEND_ARG_INFO(0, result)
  ZEND_END_ARG_INFO()
  -ZEND_BEGIN_ARG_INFO_EX(arginfo_pg_meta_data, 0, 0, 2)
  - ZEND_ARG_INFO(0, connection)
  +ZEND_BEGIN_ARG_INFO_EX(arginfo_pg_meta_data, 0, 0, 1)
  ZEND_ARG_INFO(0, table_name)
  ZEND_END_ARG_INFO()
  @@ -459,8 +458,6 @@ static PHP_METHOD(swoole_postgresql_coro, query)
  Z_PARAM_ZVAL(query)
  ZEND_PARSE_PARAMETERS_END();
  -
  -
  pg_object *pg_object = swoole_get_object(getThis());
  pg_object->request_type = NORMAL_QUERY;
  pgsql = pg_object -> conn;
  @@ -622,7 +619,6 @@ static PHP_METHOD(swoole_postgresql_coro,numRows)
  static PHP_METHOD(swoole_postgresql_coro,metaData)
  {
  - zval *pgsql_link;
  char *table_name;
  size_t table_name_len;
  zend_bool extended=0;
  @@ -635,12 +631,13 @@ static PHP_METHOD(swoole_postgresql_coro,metaData)
  size_t new_len;
  - ZEND_PARSE_PARAMETERS_START(2,2)
  - Z_PARAM_RESOURCE(pgsql_link)
  + ZEND_PARSE_PARAMETERS_START(1,1)
  Z_PARAM_STRING(table_name, table_name_len)
  ZEND_PARSE_PARAMETERS_END();
  - pgsql = (PGconn *)zend_fetch_resource(Z_RES_P(pgsql_link), "postgresql connection", le_link);
  + pg_object *pg_object = swoole_get_object(getThis());
  + pg_object->request_type = META_DATA;
  + pgsql = pg_object -> conn;
  while ((pg_result = PQgetResult(pgsql)))
  @@ -715,8 +712,6 @@ static PHP_METHOD(swoole_postgresql_coro,metaData)
  //pg_result = PQexec(pgsql, ZSTR_VAL(querystr.s));
  - pg_object *pg_object = swoole_get_object(getThis());
  - pg_object->request_type = META_DATA;
  int ret = PQsendQuery(pgsql, ZSTR_VAL(querystr.s));
  if(ret == 0)
  {
  @@ -740,12 +735,9 @@ static PHP_METHOD(swoole_postgresql_coro,metaData)
  php_swoole_check_timer((int) (redis->timeout * 1000));
  redis->timer = SwooleG.timer.add(&SwooleG.timer, (int) (redis->timeout * 1000), 0, sw_current_context, swoole_redis_coro_onTimeout);
  }*/
  - zval_ptr_dtor(pgsql_link);
  coro_save(sw_current_context);
  coro_yield();
  -
  -
  }
  /* {{{ void php_pgsql_fetch_hash */
  