create table engine Log: _LIBCPP_ASSERT '!empty()'

```
akuzm@akuzm-nix:~/ch4/ch$ ../build-clang10/programs/clickhouse-local --query "create table t engine Log as select 1 a"
/home/akuzm/ch4/ch/contrib/libcxx/include/string:3281: _LIBCPP_ASSERT '!empty()' failed. string::back(): string is empty
Aborted (core dumped)
```

https://pastebin.com/raw/txmG1SCs