AUSTIN, Texas – It’s back to welterweight for Kelvin Gastleum , who plans to stay in the division he considers his own. Take him at his word and Gastelum (18-8 MMA, 12-8 UFC) is thriving at the lighter of the two weight classes he’s bounced between in recent years. On Saturday, he faces Sean Brady (15-1 MMA, 5-1 UFC) at UFC on ESPN 52 with the intention of reentering the 170-pound mix. “I feel great, man. I haven’t felt this great in years,” Gastelum told MMA Junkie and other reporters Wednesday at a pre-fight news conference. “I haven’t been this skinny in years