fix breadcrumbs

Author: sentrivana

sentry_sdk/scope.py

@@ -247,7 +247,7 @@ def __copy__(self):
         rv._contexts = self._contexts.copy() if self._contexts else {}
         rv._extras = self._extras.copy() if self._extras else {}
 
-        rv._breadcrumbs = copy(self._breadcrumbs) if self._breadcrumbs else {}
+        rv._breadcrumbs = copy(self._breadcrumbs) if self._breadcrumbs else deque()
         rv._n_breadcrumbs_truncated = self._n_breadcrumbs_truncated
         rv._event_processors = (
             self._event_processors.copy() if self._event_processors else []