Prevent global var from being discarded at shutdown (#2530)

sentry_sdk/integrations/logging.py

@@ -91,14 +91,18 @@ def setup_once():
 
         def sentry_patched_callhandlers(self, record):
             # type: (Any, LogRecord) -> Any
+            # keeping a local reference because the
+            # global might be discarded on shutdown
+            ignored_loggers = _IGNORED_LOGGERS
+
             try:
                 return old_callhandlers(self, record)
             finally:
                 # This check is done twice, once also here before we even get
                 # the integration.  Otherwise we have a high chance of getting
                 # into a recursion error when the integration is resolved
                 # (this also is slower).
-                if record.name not in _IGNORED_LOGGERS:
+                if ignored_loggers is not None and record.name not in ignored_loggers:
                     integration = Hub.current.get_integration(LoggingIntegration)
                     if integration is not None:
                         integration._handle_record(record)