UPDATE 1-British retail sales slow in July after strong second quarter

* Retail sales rise 1.3 pct y/y, down from 2.8 pct in June * Weakest three months for retail sales since Nov 2013 * Economists say data points to subdued economy (Adds market and analyst reaction, graphic) By David Milliken and Paul Sandle LONDON, Aug 17 (Reuters) - British retail sales growth slowed broadly as expected in July after a strong second quarter, as shoppers cut back on purchases of most goods other than food, adding to worries about a fall in consumer demand ca