!13812 fix error when use context in sub thread

From: @wangnan39
Reviewed-by: @zh_qh,@kingxian
Signed-off-by: @zh_qh

mindspore/context.py

@@ -83,6 +83,7 @@ class _ThreadLocalInfo(threading.local):
     def __init__(self):
         super(_ThreadLocalInfo, self).__init__()
         self._reserve_class_name_in_scope = True
+        self.debug_runtime = False
 
     @property
     def reserve_class_name_in_scope(self):