This fixes https://github.com/ClickHouse/ClickHouse/issues/33549
The infinite loop caused because sometimes the pos of ReadBuffer overflows the end.
It happens f.e. when `MySQLPacketPayloadReadBuffer::nextImpl` might return empty buffer,
because `in.nextIfAtEnd();` could not read more bytes and thus no bytes available (pos == end).
It might happen when a network error or the connection to MySQL was closed or killed.
This leads to empty `working_buffer` but successful returning from the func.
And check `if (in.eof())` from `MySQLBinlogEventReadBuffer::nextImpl()` fails and also causes empty its `working_buffer` and successul return.
At the end `payload.ignore(1)` and `payload.read(c)` produces the infinite loop since it is not eof() and ++pos overflows the end of the buffer.
Should be tested by `test_mysql_kill*` from test.py
3cea474ccf