Coerce None values into strings in logentry params. (#4121)

Nice rendering of log messages containing parameters that are `None`
values does not work. There we coerce `None` values into strings to have
nicer messages in Sentry UI.

Fixes #3660

Author: antonpirker

sentry_sdk/integrations/logging.py

@@ -248,7 +248,11 @@ def _emit(self, record):
         else:
             event["logentry"] = {
                 "message": to_string(record.msg),
-                "params": record.args,
+                "params": (
+                    tuple(str(arg) if arg is None else arg for arg in record.args)
+                    if record.args
+                    else ()
+                ),
             }
 
         event["extra"] = self._extra_from_record(record)