Merge pull request #352 from ytrezq/patch-1

Transfer extractor : fix string compare bug by switching to case insensitive string comparison.

Author: medvedev1088

ethereumetl/service/token_transfer_extractor.py

@@ -40,7 +40,7 @@ def extract_transfer_from_log(self, receipt_log):
             # This is normal, topics can be empty for anonymous events
             return None
 
-        if topics[0] == TRANSFER_EVENT_TOPIC:
+        if (topics[0]).casefold() == TRANSFER_EVENT_TOPIC:
             # Handle unindexed event fields
             topics_with_data = topics + split_to_words(receipt_log.data)
             # if the number of topics and fields in data part != 4, then it's a weird event