Mike Tyson has been flooded with supportive messages by boxing fans after emotionally admitting he’s fighting Jake Paul to show age is just a number. At the age of 58, many are writing off the heavyweight icon as he prepares to return to the ring. After all, Paul is 31 years his junior and recently dispatched Mike Perry to clock up the 10th win of his professional career. Speaking in a clip uploaded on his Instagram account, Tyson opened up on why he was fighting Paul. “I want to change biology, I want to change the way people think about age,” he said. The boxing icon then added: “People thin…