Specifying `--confirm` and `--repository` results in error for `func create`

[lance]

When specifying both --confirm and --repository in a call to func create an error is thrown in spite of valid input.

❯ kn func create -c -r https://github.com/boson-project/test-language-pack
? Function Path: foo
? Language Runtime:
? Template: http
Error: Required flag "language" not set.
Available language runtimes are:
  go

Error: exit status 1

[lance]

Update: when you actually type in go at the Language Runtime: prompt, it works fine.

❯ kn func create -c -r https://github.com/boson-project/test-language-pack
? Function Path: foo
? Language Runtime: go
? Template: http
Created go Function in /home/lanceball/src/github.com/visionmedia/superagent/foo

…as-text [$?] is  v7.1.1 via  v16.13.2 on   rh-serverless took 10s