SQLite: Check constraint to check if value is in list causes infinite loop
Try

`constraints=[Check("test in ('http', 'smb')")]` Oh, derp. Thanks!
Maybe this isn't supported, but it seems like a parse error to me. 

Minimal example:

```python
from peewee import SqliteDatabase, CharField, Check
from playhouse.signals import Model

class Test(Model):
    database = SqliteDatabase('test.db')
    database.connect()
    test = CharField(constraints=Check("test in ('http','smb')"))

def main():
    database = SqliteDatabase('test.db')
    database.connect()
    Test._meta.database = database
    database.create_tables([Test])

if __name__ == '__main__':
    main()
```

Running this code causes an infinite loop in `create_tables`. The following works just fine in SQLite: 

```sql
create table test(test varchar CHECK(test in ('http','smb')));
insert into test values ('abc');
>> Error: CHECK constraint failed: test
```

EDIT: Version numbers are Python 3.6.8, peewee 3.9.5