slapos.recipe.downloadunpacked will only accept 'false' as false value

slapos/recipe/cmmi/__init__.py

@@ -292,7 +292,7 @@ class Recipe(object):
             try:
                 opt = self.options.copy()
                 opt['destination'] = compile_dir
-                opt['strip-top-level-dir'] = 'False'
+                opt['strip-top-level-dir'] = 'false'
                 slapos.recipe.downloadunpacked.Recipe(
                     self.buildout, self.name, opt).install()
             except: