Vietnam is restarting passenger flights with six Asian cities as it moves to shore up an economy battered by the coronavirus pandemic by boosting business activity. Foreigners travelling for business or study, along with Vietnamese nationals and their family members, will be allowed in from the southern Chinese city of Guangzhou, South Korea’s Seoul, Japan’s Tokyo, and Taipei, the government said on Tuesday, adding that flights to and from Cambodia’s Phnom Penh and Laos’ Vientiane would start…