issue 234

As I mentioned in the issue, I'm not sure why last_match is expected to have anything.  I don't see where it could have been previously used.

I just added to the conditional to check for nil and that the length is at least 2 since last_match[1] is referenced.  Perhaps the last_match portion could be removed completely but I wanted to err on the side of caution.

This got it working for me.  Without this, chef-client runs after the initial one would fail.