Work around Clang whining about UTF-8

git-svn-id: svn+ssh://svn.gnucash.org/repo/gnucash/trunk@23434 57a11ea4-9604-0410-9ed3-97b8803252fd
Fix make check after r23429 broke it.

git-svn-id: svn+ssh://svn.gnucash.org/repo/gnucash/trunk@23435 57a11ea4-9604-0410-9ed3-97b8803252fd