Merge branch 'ja/do-not-ask-needless-questions'

Git sometimes gives an advice in a rhetorical question that does not require an answer, which can confuse new users and non native speakers. Attempt to rephrase them. * ja/do-not-ask-needless-questions: git-filter-branch: be more direct in an error message read-tree -m: make error message for merging 0 trees less smart aleck usability: don't ask questions if no reply is required