Fix r3-alpha-based bootstrap when a commit isn't specified
Fix r3-alpha-based bootstrap when a commit isn't specified

A "fake blank" (none) was being molded out as the word none, instead
of the desired _.

codebybrett/ren-c,hostilefork/rebol,rgchris/ren-c,hostilefork/rebol,rgchris/ren-c,hostilefork/rebol,giuliolunati/ren-c,draegtun/ren-c,rgchris/ren-c,kealist/ren-c,hostilefork/rebol,rgchris/ren-c,draegtun/ren-c,draegtun/ren-c,kealist/ren-c,giuliolunati/ren-c,codebybrett/ren-c,codebybrett/ren-c,draegtun/ren-c,codebybrett/ren-c,kealist/ren-c,kealist/ren-c,giuliolunati/ren-c,kealist/ren-c,kealist/ren-c,draegtun/ren-c,draegtun/ren-c,giuliolunati/ren-c,hostilefork/rebol,rgchris/ren-c,codebybrett/ren-c,codebybrett/ren-c,hostilefork/rebol,giuliolunati/ren-c