Returns number of hunt log entries of a given hunt.

def CountHuntLogEntries(self, hunt_id, cursor=None):
    """Returns number of hunt log entries of a given hunt."""
    hunt_id_int = db_utils.HuntIDToInt(hunt_id)

    query = ("SELECT COUNT(*) FROM flow_log_entries "
             "FORCE INDEX(flow_log_entries_by_hunt) "
             "WHERE hunt_id = %s AND flow_id = hunt_id")
    cursor.execute(query, [hunt_id_int])
    return cursor.fetchone()[0]