one last TestRunner config fix

e.g.
http://www.cpantesters.org/cpan/report/a4443dc6-6bf8-1014-ab3f-ba6b6dcf0d55
http://www.cpantesters.org/cpan/report/61b28651-6bfa-1014-bda4-156af1ea0ff0
Dist-Zilla-Plugin-ModuleBuildTiny-Fallback-0.009

          - more fixes as in 0.008 and 0.007