(Fixes typo in paragraph 2 and dropped word ‘the’ in last paragraph) BELGRADE (Reuters) – Workers from automaker Stellantis’ Serbian plant blocked the main highway in the capital Belgrade on Wednesday to protest planned layoffs as part of a switch to producing electric vehicles. Last month, the company offered some of its 2,000 workers at its Serbian plant a choice between moving abroad for two years to re-train in electric car production, or taking redundancy – a move that was opposed by unions. The offer came after Serbia and Stellantis in April agreed a deal of over 190 million euros ($199….