api/swagger/firecracker-v0.1.yaml: updated
api/swagger/firecracker-v0.1.yaml: updated

Updated the firecracker-v0.1. yaml file to reflect that the vsock
guest_cid is an integer.

Signed-off-by: Alexandru Agache <69826f943dd6ae0c808126caf67f094b6aee96c2@amazon.com>

firecracker-microvm/firecracker,firecracker-microvm/firecracker,firecracker-microvm/firecracker,firecracker-microvm/firecracker,firecracker-microvm/firecracker