message: genop: fix template error
  Rewrite a conditional in a template to be syntactically valid.
diff: @@ -265,7 +265,7 @@ func {{$.Op.Name}}{{CamelCase .RenameTo}}(value {{GoType .Type}}) {{$.Op.Name}}A
  {{- else }}
  {{- if .DescribeOutputs}}
  //
  -{{- if ((len .OutArgs) eq 1) }}
  +{{- if eq (len .OutArgs) 1 }}
  // Returns {{range .OutArgs}}{{MakeComment .Description}}{{end}}
  {{- else }}
  // Returns:
  