config: add Initrd to known fields

config/config.go

@@ -258,6 +258,7 @@ func checkUnknownFields(data []byte) (string, error) {
 		"Enable_Syscalls",
 		"Disable_Syscalls",
 		"Suppressions",
+		"Initrd",
 	}
 	f := make(map[string]interface{})
 	if err := json.Unmarshal(data, &f); err != nil {

vm/vm.go

@@ -33,7 +33,7 @@ type Config struct {
 	Index      int
 	Workdir    string
 	Bin        string
-	Initrd	   string
+	Initrd     string
 	Kernel     string
 	Cmdline    string
 	Image      string