on localhost, loading Julia before Python causes error, but loading python before julia is fine

cc @mdboom -

Not sure what to make of this issue, since this appears to be a problem primarily on localhost (on `master`, can't reproduce on `extremely-alpha`). If you run these cells sequentially, it succeeds:

```
%% py

[1,12,1]

%% plugin
{
"languageId": "jl",
"displayName": "julia",
"codeMirrorMode": "julia",
"keybinding": "j",
"url": "https://keno.github.io/julia-wasm/julide/julide.js",
"module": "jlodide",
"evaluator": "runJulia",
"pluginType": "language"
}

%% jl
Sys.ARCH

```

But this fails:

```
%% plugin
{
"languageId": "jl",
"displayName": "julia",
"codeMirrorMode": "julia",
"keybinding": "j",
"url": "https://keno.github.io/julia-wasm/julide/julide.js",
"module": "jlodide",
"evaluator": "runJulia",
"pluginType": "language"
}

%% jl
Sys.ARCH

%% py
[1,12,1]

```

It could be the Julia is clobbering something somewhere in the setup that prevents python from working as expected, in which case it'd be a bug on the `julia-wasm` end.