Fix wmt20 incongruency

wmt_vat.py

@@ -61,8 +61,8 @@ _CONFIGS = {
 
 _PATHS = {
     f"{year}_{pair}": {
-        "src" : os.path.join(_BASE_URL, year, f"vat_newstest20{year[3:]}-{pair.replace('_', '')}-src.{pair.split('_')[0]}"),
-        "ref" : os.path.join(_BASE_URL, year, f"vat_newstest20{year[3:]}-{pair.replace('_', '')}-ref.{pair.split('_')[1]}")
+        "src" : os.path.join(_BASE_URL, year, f"vat_newstest20{year[3:]}-{pair.replace('_', '')}-src.{pair.split('_')[0]}{'.txt' if year == 'wmt20' else ''}"),
+        "ref" : os.path.join(_BASE_URL, year, f"vat_newstest20{year[3:]}-{pair.replace('_', '')}-ref.{pair.split('_')[1]}{'.txt' if year == 'wmt20' else ''}")
     } for year, pairs in _CONFIGS.items() for pair in pairs
 }