By Mia Shanley and Helena Soderpalm STOCKHOLM (Reuters) – Painful memories of the Internet bubble more than a decade ago are likely to cut the risk that tech stocks get too frothy as online newcomers Zalando and Rocket Internet prepare to make market debuts, the CEO of Sweden’s Kinnevik said. The Swedish company is the biggest investor in German online fashion retailer Zalando and has an 18.5 percent stake in venture capital company Rocket Internet, which has ambitions to be the largest Internet business outside the United States and China. …