GLOBAL MARKETS-Shares up on China relief, Ukraine strains remain

* China GDP grows 7.4 pct y/y, just pipping forecasts * Markets relieved growth was not much weaker * European shares rebound after recent falls * Nikkei leads the way, encouraged by late rally on Wall St * UK, euro zone data in focus, Ukraine tensions simmer By Marc Jones LONDON, April 16 (Reuters) - Share markets made broad gains on Wednesday after China reported economic growth a touch above forecasts, a relief for investors who had feared a much weaker outcome. C