Merge branch 'ah/doc-empty-string-is-false' into maint

Doc update. * ah/doc-empty-string-is-false: doc: clarify "config --bool" behaviour with empty string

Junio C Hamano committed Sep 10, 2017 at 17:03 UTC b438722c067ce941d576ab3cf8f959119433f2d2

No changes.