LONDON (Reuters) – British Airways said it was investigating a technical issue on Wednesday after customers complained online about an IT outage and its departures board for London’s Heathrow showed flights being delayed. “We’re investigating and working hard to resolve a technical issue and apologise for the inconvenience. We will provide further updates as quickly as possible,” the British Airways verified account said on Twitter. The online departure board showed flights at Heathrow were delayed, with a few cancelled. “Hey @British_Airways, our captain has tried to call, email to let you kn…