How do I fix sticking/tight hydraulic brake calipers?
Most likely, while you had the wheel out, the brake lever was pulled, and the piston position was reset too close to the disc. 

You need to remove the brake pads, and very gently push the pistons all the way back into the caliper. 

Then replace the wheel, and pump the brake lever. It should take 2 or 3 pumps to feel normal again. 

Hope that helps.