broken css and js in file:///run/ local file.

## Issue:
Broken css on page opened when ```jupyter notebook``` is executed.(automatically opened)

* ```http://localhost:8888/``` works just fine.
## Log:

```
(AI) [jagadeesh@maxfunc ~]$ jupyter notebook
[I 14:39:42.300 NotebookApp] Writing notebook server cookie secret to /run/user/1000/jupyter/notebook_cookie_secret
[I 14:39:43.659 NotebookApp] Serving notebooks from local directory: /home/jagadeesh
[I 14:39:43.659 NotebookApp] The Jupyter Notebook is running at:
[I 14:39:43.660 NotebookApp] http://localhost:8888/?token=038aec47d4d27edbd623aeafef0c58e32ad3ba477b9c5c9e
[I 14:39:43.660 NotebookApp] Use Control-C to stop this server and shut down all kernels (twice to skip confirmation).
[C 14:39:43.761 NotebookApp]

To access the notebook, open this file in a browser:
file:///run/user/1000/jupyter/nbserver-3144-open.html
Or copy and paste one of these URLs:
http://localhost:8888/?token=038aec47d4d27edbd623aeafef0c58e32ad3ba477b9c5c9e
[I 14:43:53.826 NotebookApp] Kernel started: 3d404127-2f27-4d04-b4d8-adb108db7df5
[I 14:43:54.840 NotebookApp] Adapting to protocol v5.1 for kernel 3d404127-2f27-4d04-b4d8-adb108db7df5
```
This automatically opens ``` file:///run/user/1000/jupyter/nbserver-3144-open.html``` where css is broken.

## environment

```Linux maxfunc 5.0.9-2-MANJARO #1 SMP PREEMPT Sun Apr 21 07:11:08 UTC 2019 x86_64 GNU/Linux```

### Server Information:

```
You are using Jupyter notebook.

The version of the notebook server is: 5.7.8
The server is running on this version of Python:

Python 3.7.3 (default, Mar 27 2019, 22:11:17)
[GCC 7.3.0]
```

### Current Kernel Information:

```
Python 3.7.3 (default, Mar 27 2019, 22:11:17)
Type 'copyright', 'credits' or 'license' for more information
IPython 7.5.0 -- An enhanced Interactive Python. Type '?' for help.
```

**Browser** : ```Firefox Developer Edition 67.0b12 (64-bit)```

## Additional info

**Firefox js console output:**
```
Loading failed for the with source “file:///static/components/es6-promise/promise.min.js?v=f004a16cb856e0ff11781d01ec5ca8fe”. nbserver-3144-open.html:18:1
Loading failed for the <script> with source “file:///static/components/preact/index.js?v=00a2fac73c670ce39ac53d26640eb542”. nbserver-3144-open.html:19:1
Loading failed for the <script> with source “file:///static/components/proptypes/index.js?v=c40890eb04df9811fcc4d47e53a29604”. nbserver-3144-open.html:20:1
Loading failed for the <script> with source “file:///static/components/preact-compat/index.js?v=aea8f6660e54b18ace8d84a9b9654c1c”. nbserver-3144-open.html:21:1
Loading failed for the <script> with source “file:///static/components/requirejs/require.js?v=951f856e81496aaeec2e71a1c2c0d51f”. nbserver-3144-open.html:22:1
ReferenceError: require is not defined nbserver-3144-open.html:24:7
Loading failed for the <script> with source “file:///static/tree/js/main.min.js?v=255071046c54ea22f16c5bbbdcb5fca8”. nbserver-3144-open.html:347:1

```

**screenshot**:


Reproduce the automatic opening of file:///run/user/1000/jupyter/nbserver-3144-open.html after running jupyter notebook, then inspect that generated HTML and the Firefox console errors for the file:///static asset URLs. Done means the automatically opened local page loads its CSS and JavaScript instead of failing to load the referenced assets.

Written by the indexing model from the issue text.