ProgrammingError during get_or_create
I'm using peewee-async so it may have to do with that library. Checking.. 
I'm running Postgres with peewee 2.10.2 

When running the following code: 

```
Author.get_or_create(
    id=author['id'],
    defaults=author
)
```

I get syntax error at or near "AS" `LINE 1: ...t1"."country" FROM "author" AS t1 WHERE ("author" AS t1 AND ...` It happens for the second AS. The full query is the following.

```
SELECT "t1"."id", "t1"."ctime", "t1"."mtime", "t1"."name", "t1"."gender", "t1"."country" 
FROM "author" AS t1 
WHERE ("author" AS t1 AND ("t1"."id" = %s)) [16667]
```