fix postcode pattern for Mozambique

Optional groups are not implemented yet.

nominatim/tokenizer/sanitizers/clean_postcodes.py

@@ -57,7 +57,8 @@ class _PostcodeSanitizer:
         if match is None:
             return None
 
-        return self.matcher.normalize(country, match), ' '.join(match.groups())
+        return self.matcher.normalize(country, match),\
+               ' '.join(filter(lambda p: p is not None, match.groups()))
 
 
 

settings/country_settings.yaml

@@ -1386,8 +1386,7 @@ mz:
     languages: pt
     names: !include country-names/mz.yaml
     postcode:
-      pattern: "(dddd)-?(dd)?"
+      pattern: "(dddd)(?:-dd)?"
-      output: \1-\2
 
 
 # Namibia (Namibia)