Fix to avoid error if middleware returns non-string req.body
Fix to avoid error if middleware returns non-string req.body

Fiware/ops.Health,Fiware/ops.Health,Fiware/ops.Health,Fiware/ops.Health,telefonicaid/fiware-health,telefonicaid/fiware-health,telefonicaid/fiware-health,telefonicaid/fiware-health,telefonicaid/fiware-health,Fiware/ops.Health