Fix an incorrect use of the now-defunct `ErrorProtocol` protocol (has been renamed to `Swift.Error`)
Fix an incorrect use of the now-defunct `ErrorProtocol` protocol (has been renamed to `Swift.Error`)

apple/swift-package-manager,mxcl/swift-package-manager,haskellswift/swift-package-manager,JGiola/swift-package-manager,apple/swift-package-manager,abertelrud/swift-package-manager,haskellswift/swift-package-manager,vmanot/swift-package-manager,apple/swift-package-manager,haskellswift/swift-package-manager,abertelrud/swift-package-manager,abertelrud/swift-package-manager,abertelrud/swift-package-manager,sschiau/swift-package-manager,vmanot/swift-package-manager,JGiola/swift-package-manager,apple/swift-package-manager,vmanot/swift-package-manager,sschiau/swift-package-manager,vmanot/swift-package-manager,abertelrud/swift-package-manager,vmanot/swift-package-manager,mxcl/swift-package-manager,sschiau/swift-package-manager,apple/swift-package-manager,mxcl/swift-package-manager,JGiola/swift-package-manager,sschiau/swift-package-manager,haskellswift/swift-package-manager,JGiola/swift-package-manager,mxcl/swift-package-manager,sschiau/swift-package-manager,JGiola/swift-package-manager