unify sign key default value, fixes chainguard-dev#1114

Signed-off-by: Soner Sayakci <s.sayakci@shopware.com>

pkg/cli/sign.go

@@ -173,7 +173,7 @@ func Sign() *cobra.Command {
 		},
 	}
 
-	cmd.Flags().StringVarP(&o.Key, "signing-key", "k", "local-melange.rsa", "The signing key to use.")
+	cmd.Flags().StringVarP(&o.Key, "signing-key", "k", "melange.rsa", "The signing key to use.")
 
 	return cmd
 }