(Reuters) – Ukraine’s central bank said on Friday it was making a number of changes to the foreign currency market to make it more stable and reduce pressure on the country’s international reserves. From May 4, the limits of banks’ open long and short currency positions will be cut to 5% of their regulatory capital, down from 15%. The changes were announced in a statement posted on the bank’s website. In addition, banks are temporarily prohibited from concluding a number of money market derivative contracts, except for swaps, and from April 30, banks will suspend the practice of issuing new sa…