Properly handle overwriting values in a wad-level config.

This only was a problem for values that we were geenerating a property
for.

dcc/doom_base.py

@@ -27,6 +27,7 @@ class Wad(dcc.config.Base):
                         self._config[k][sk] = v[sk]
                 else:
                     self._config[k] = v
+        self.finalize()
 
     def run(self, parsed_args):
         self.wad_init(parsed_args)