Former UFC lightweight titleholder Charles Oliveira has responded to Islam Makhachev’s concerns. In just under two weeks, Charles Oliveira and Islam Makhachev will lock horns in the main event of UFC 280 in Abu Dhabi for the vacant lightweight title. Oliveira is currently riding an impressive 11-fight win streak, defeating some of the best lightweights in the world on his way to capturing the 155lb title. Stoppage wins over Michael Chandler, Dustin Poirier and Justin Gaethje all within one year tells you all you need to know about ‘do Bronx.’ As for Makhachev, who holds a 10-fight win streak, it’s…