Problem with CLI commands using angle brackets nested inside curly braces

[rwestphal]

Example command to illustrate the problem:
"show configuration running [{<json|xml>|with-defaults}]"

Testing this command in the CLI I got this:

ripd# show configuration running json    
  with-defaults  Show default values
  xml            Change output format to XML
  <cr>

In the command above, the expected behavior would be to accept either json or xml only once. The CLI shouldn't accept both options as <json|xml> should be counted a single option within the curly braces