rowData can leak *sql.Rows

[haaawk]

If rows.Columns() returns an error, rowData will return without closing rows. As a result an SQLite read transaction will never end and possibly block writes to the database.

https://github.com/zknill/sqledge/blob/main/pkg/pgwire/postgres.go#L317

[haaawk]

This will probably block the replication if it happens.