By Elvira Pollina and Mathieu Rosemain MILAN/PARIS (Reuters) -Bertelsmann’s RTL Group has scrapped a plan to sell its controlling stake in French TV group M6, the Luxembourg-based media group said on Monday, confirming a Reuters report. Dropping the sale of RTL’s 48.3% stake in M6 means that Germany’s Bertelsmann will have to wait five years before considering any new bids for the French TV network, known for its high margins in a sector challenged by the competition of U.S. streaming platforms such as Netflix, Amazon Prime and Disney+. M6 will apply for a new five-year broadcast authorisation…