I believe they altered the landing gear so it extends upon deployment, giving it a bit more height, but that's not enough. They can't just put longer legs, there isn't enough room. There's stuff there (cables, devices, bulkheads ...) and moving them requires a significant redesign. For the main gears, they would have to be attached further away from the center lest they bump into each other, which means the wings and fuselage would have to be stronger to accommodate for it. Very quickly you're just designing a new plane.