Merge pull request #4966 from takluyver/sign-blank-app-argv

Ignore sys.argv in NotebookNotary

when creating a BaseIPythonApplication just for its profile_dir

IPython/nbformat/sign.py

@@ -84,7 +84,7 b' class NotebookNotary(LoggingConfigurable):'
         if app is None:
             # create an app, without the global instance
             app = BaseIPythonApplication()
-            app.initialize()
+            app.initialize(argv=[])
         return app.profile_dir
     
     algorithm = Enum(algorithms, default_value='sha256', config=True,