Hello together!

I've noticed that when you replay a build and make changes to the Jenkinsfile in the text area in the browser (and therefor basically replace it), it still tries to load the Jenkinsfile from source, which is unnecessary. I only noticed because we're already running tight with the Github API rate limit (which is of course unrelated).

Example:

Replayed #21
14:55:40 Connecting to https://api.github.com using some-user/****** (checkout)
14:55:40 GitHub API Usage: Current quota has 2147 remaining (0 under budget). Next quota of 5000 in 30 min
Obtained Jenkinsfile from 8522ab599dbab8763d57475e2879e5fd8aca1fd1