added str.lower check

If someone can TEST my code quickly we can accept it and go

freqtrade/main.py

@@ -48,15 +48,13 @@ def refresh_whitelist(whitelist: List[str]) -> List[str]:
                 'Ignoring %s from whitelist (reason: %s).',
                 pair, status.get('Notice') or 'wallet is not active'
             )
-        # Wallet is going to be delisted (and cause a loss)
-        delisted = 'delisted'
-        if delisted in str(status['Notice']):
+        # Wallet will be delisted soon (and cause a loss)
+        if 'delisted' in str(status['Notice']).lower():
             sanitized_whitelist.remove(pair)
             logger.info(
                 'Ignoring %s from whitelist (reason: %s).',
                 pair, status.get('Notice') or 'wallet will be delisted soon'
             )
-
             
     # We need to remove pairs that are unknown
     final_list = [x for x in sanitized_whitelist if x in known_pairs]