oidc_client_react - minor build & run issues

[ftang001]

Two tips to get the oidc_client_react sample app running:

1. HOST environment variable needs to be unset

2. With recent versions of node.js (17+) and openssl I had to enable legacy openssl hashing algorithms (MD4) for webpack - see e.g. https://stackoverflow.com/questions/69394632/webpack-build-failing-with-err-ossl-evp-unsupported

I'm a newbie with node.js, so of the suggested fixes, setting an alternative OPENSSL_CONF was the quickest and most effective. It might be preferable for someone who knows their way around to configure/hack webpack to use something else, but I gather this is non-trivial: https://githubmemory.com/repo/webpack/webpack/issues/13572.

Thanks - James.