Sir Seewoosagur Ramgoolam International Airport in Mauritius (MRU/FIMP) is currently a 2, however as seen on the wikipedia page there are several B777/B747/A380 flights a day, which should bring it up to a 4 if I'm not mistaken?
https://en.wikipedia.org/wiki/Sir_Seewoosagur_Ramgoolam_International_Airport#Airlines_and_destinations