Avoid using distinct here, it is too expensive on database side

trans/management/commands/rebuild_index.py

@@ -22,7 +22,7 @@ class Command(BaseCommand):
                 trans.search.create_target_index(lang = lang.code)
 
         with trans.search.get_source_writer(buffered = False) as writer:
-            for unit in Unit.objects.values('checksum', 'source', 'context', 'translation_id').distinct().iterator():
+            for unit in Unit.objects.values('checksum', 'source', 'context', 'translation_id').iterator():
                 Unit.objects.add_to_source_index(
                     unit['checksum'],
                     unit['source'],