By Catarina Demony LISBON (Reuters) – Portugal blocked the sale of a 10 million euro ($10.4 million) luxury house over a “strong conviction” it belonged to sanctions-hit Russian billionaire Roman Abramovich, Foreign Minister Joao Cravinho said on Saturday. The property registry of the mansion in the luxury Quinta do Lago resort in the Algarve was frozen – meaning it cannot be sold, rented or mortgaged – on March 25 at the request of the foreign ministry, a month after Russia’s full invasion of Ukraine. “We have a strong conviction, which hasn’t been fully confirmed, the house belongs to Roman …