t / t3901 / utf8.txton commit tests: make use of the test_must_be_empty function (d3c6751)
   1: to be sourced in t3901 -- this is utf8
   2GIT_AUTHOR_NAME="Áéí óú" &&
   3GIT_COMMITTER_NAME=$GIT_AUTHOR_NAME &&
   4export GIT_AUTHOR_NAME GIT_COMMITTER_NAME