Adjust Makefile.am for new runTests.py.in

Left over from r23392

git-svn-id: svn+ssh://svn.gnucash.org/repo/gnucash/trunk@23403 57a11ea4-9604-0410-9ed3-97b8803252fd
Release 1.5.8

git-svn-id: svn+ssh://svn.gnucash.org/repo/gnucash/trunk@23404 57a11ea4-9604-0410-9ed3-97b8803252fd