make runUnitTest aware of w3-validator location

stack/erp5/buildout.cfg

@@ -392,6 +392,7 @@ initialization =
   sys.path[:0] = sum((
     glob.glob(os.path.join(x, 'Products', '*', 'tests'))
     for x in os.getenv('INSERT_PRODUCTS_PATH', '').split(os.pathsep)), [])
+  os.environ['CGI_PATH'] = '${w3-validator:location}/httpd/cgi-bin'
 
 [test_suite_runner]
 # XXX: Workaround for fact ERP5Type is not an distribution and does not