FRANKFURT (Reuters) - European Central Bank interest rates are not yet close to the so-called reversal rate, where low rates actually hamper the banking sector rather than stimulate lending, ECB Vice President Luis de Guindos said on Wednesday.The negative side effects of the ECB's ultra loose policy are nevertheless becoming more evident and require monitoring, de Guindos told a news conference. The ECB cut its deposit rate to a record low minus 0.5% in September and markets see scope for a..