This issue is hard to reproduce, it happens 10 times in last 24 hours

duration_hr is a field with type Decimal (13, 4), I found some abnormal conversion during the ClickHouse replication, as below:
```
MySQL     ClickHouse
0.3333 -> -2147483653.2202
0.5000 -> -2147483653.0535
0.1667 -> -2147483653.3868
0.0833 -> -2147483653.4702
0.7500 -> -2147483652.8035
```
As you can see, a weired one among the normal ones:
```
│ HCAC    │ 2020-10-22 07:10:00 │           0.3333 │
│ HCAC    │ 2020-10-22 07:15:00 │           0.3333 │
│ HCAC    │ 2020-10-22 07:20:00 │           0.3333 │
│ HCAC    │ 2020-10-22 07:25:00 │           0.3333 │
│ HCAC    │ 2020-10-22 07:30:00 │           0.3333 │
│ HCAC    │ 2020-10-22 07:35:00 │ -2147483653.2202 │
│ HCAC    │ 2020-10-22 07:40:00 │           0.3333 │
│ HCAC    │ 2020-10-22 07:45:00 │           0.3333 │
│ HCAC    │ 2020-10-22 07:50:00 │           0.3333 │
│ HCAC    │ 2020-10-22 07:55:00 │           0.3333 │
│ HCAC    │ 2020-10-22 08:00:00 │           0.3333 │
│ HCAC    │ 2020-10-22 08:05:00 │           0.3333 │
```


-Lyon
if (columns_null_set[null_index])
            {
                row.push_back(Field{Null{}});
            }
            else
            {
                auto meta = table_map->column_meta[i];
                auto field_type = table_map->column_type[i];
                if (field_type == MYSQL_TYPE_STRING)
                {
                    if (meta >= 256)
                    {
                        UInt8 byte0 = meta >> 8;
                        UInt8 byte1 = meta & 0xff;
                        if ((byte0 & 0x30) != 0x30)
                        {
                            field_len = byte1 | (((byte0 & 0x30) ^ 0x30) << 4);
                            field_type = byte0 | 0x30;
                        }
                        else
                        {
                            field_len = byte1;
                            field_type = byte0;
                        }
                    }
                    else
                    {
                        field_len = meta;
                    }
                }