Fix compiler error on wasm with deault features.

[ar37-rs]

• getrandom also supported on wasm32: rust-random/getrandom@d3aa089

[vavrusa]

Hi! wasm32-unknown-unknown isn't always running inside a browser, and 0.8.1 silently breaks for all other runtimes that do not provide the JS interfaces. Would you consider putting this behind a feature flag (js) just like getrandom does it?

[tkaitchuck]

@ar37-rs Based on this, and:
#143
#141
#140
And the recomended practices here:
https://docs.rs/getrandom/latest/getrandom/#webassembly-support

I am reverting these changes to the toml file.