Fix for failng validateEveryToJSON test: "Cardano.Wallet.Api.Types, verify that every type used with JSON content type in a servant API has compatible ToJSON and ToSchema instances using validateToJSON., ApiNetworkClock"

Author: Piotr Stachyra

specifications/api/swagger.yaml

@@ -581,7 +581,6 @@ x-networkInformationNtpStatus: &networkInformationNtpStatus
       properties:
         quantity:
           type: integer
-          minimum: 0
           example: 14
         unit:
           type: string