My honda civic gives me a SHH-SHH-SHH noise as i start to accelerate 1-20 mile speed in the morning.?

This will reduce much when i drive few miles. my dealer says its the brake pads being rusty,gives such a noise which will go off eventually. .This is a car that was lying with dealer for sale in a garage for few months, so dealer says it is all about rusty break. Is it normal?