notebook rename does not respect url prefix

[hhuuggoo]

the url in the location bar changes incorrectly when the notebook is renamed if a url prefix is set

I'm going to try looking at this later today if it's truly an outstanding issue

[minrk]

Should be fixed by #5231

[takluyver]

The most challenging thing about fixing bugs in IPython: doing it before Min does ;-)

[ivanov]

I 👍 what @takluyver said.

[hhuuggoo]

awesome @minrk thanks!