db_sql_render() doesn't pass three dots

[jarodmeng]

I have a package RPresto that extends the db_sql_render() generic for Presto connections (code link). The extended db_sql_render() function has an added argument, use_presto_cte. The call stack goes from dbplyr::db_sql_render() to RPresto::db_sql_render.PrestoConnection(), so the passing of the use_presto_cte arg relies on the three dot ellipsis in dbplyr::db_sql_render(). However, in dbplyr 2.4.0, db_sql_render() doesn't pass on the ellipsis (see code link).

Happy to provide a quick PR to add the ellipsis passing to the function.

[hadley]

A PR would be great, thanks! (You might also want to consider using sql_options in your code).