(you don't have to strictly follow this form)

It seems that CH doesn't support  `FORMAT CustomSeparated` with http request
https://github.com/ClickHouse/ClickHouse/issues/12744#issuecomment-663738562

When I make a request with `format_custom_field_delimiter='^'`, I got an error
```
Code: 49, e.displayText() = DB::Exception: There is no checkpoint (version 20.1.2.4 (official build)) 
```
Bash script:
```
#!/bin/bash

find . -type f -name 'j.log' | while read f; do
  curl "http://localhost:8123
/?query=INSERT%20INTO%20mydb%20FORMAT%20CustomSeparated%20SETTINGS%20format_custom_escaping_rule%3D%27CSV%27%2C%20format_custom_field_delimiter%20%3D%20%27%5E%27" --data-binary "@${f}"
done
```
But all is OK, when I do it with client:
```
cat j.log |clickhouse-client  -q "INSERT into mydb FORMAT CustomSeparated SETTINGS format_custom_escaping_rule='CSV', format_custom_field_delimiter = '^'"
```


**How to reproduce**
* Which ClickHouse server version to use
 version 20.13.1.1 and github build `commit 6e34a0b71efc0e5af1cfb05b77a5e7b2568a2e49`
* Which interface to use, if matters
* Non-default settings, if any
* `CREATE TABLE` statements for all tables involved
```
CREATE TABLE mydb
(
	datetime  String,
	d1 String,
	d2 String
)
engine=MergeTree()
ORDER BY d1
SETTINGS index_granularity = 8192;
```
* Sample data for all these tables, use [clickhouse-obfuscator](https://github.com/ClickHouse/ClickHouse/blob/master/programs/obfuscator/Obfuscator.cpp#L42-L80) if necessary

j.log:
```
2021-Jan^d1^d2
```

* Queries to run that lead to unexpected result

**Expected behavior**
A clear and concise description of what you expected to happen.

**Error message and/or stacktrace**
If applicable, add screenshots to help explain your problem.

**Additional context**
Add any other context about the problem here.

if (const auto & constraints = metadata_snapshot->getConstraints(); !constraints.empty())
                out = std::make_shared<CheckConstraintsBlockOutputStream>(
                    query.table_id, out, out->getHeader(), metadata_snapshot->getConstraints(), context);
            
            
            out = std::make_shared<AddingDefaultBlockOutputStream>(
                out, query_sample_block, out->getHeader(), metadata_snapshot->getColumns(), context);
            
            
            
            
            if (!(context.getSettingsRef().insert_distributed_sync && table->isRemote()) && !no_squash && !query.watch)
            {
                out = std::make_shared<SquashingBlockOutputStream>(
                    out,
                    out->getHeader(),
                    context.getSettingsRef().min_insert_block_size_rows,
                    context.getSettingsRef().min_insert_block_size_bytes);
            }
            auto out_wrapper = std::make_shared<CountingBlockOutputStream>(out);
            out_wrapper->setProcessListElement(context.getProcessListElement());
            out = std::move(out_wrapper);
            out_streams.emplace_back(std::move(out));
        }
    }
    
    if (is_distributed_insert_select)
    {