Updates the link record to indicate that it has been processed

db.rs

pub fn mark_link_as_processed(conn: &SqliteConnection, link_title: &str) ->Result<usize, diesel::result::Error> {
    let u_stmt = format!("UPDATE links_processed SET processed=1 WHERE title='{}';", link_title.replace("'", "''"));
    let update = sql::<Bool>(&u_stmt);
    update.execute(conn)
}