Needs validateAuthority flag to work with b2clogin.com redirects

[anders-lundgren]

Great package, thanks for putting this together! I even thought this was the official MS package since it was featured on TechNet: https://social.technet.microsoft.com/wiki/contents/articles/52573.azure-ad-b2c-secure-your-reactjs-frontend.aspx

One small issue, the recommended login redirect to <your-domain>.b2clogin.com requires the flag validateAuthority to be set to false when calling Msal.UserAgentApplication(): https://docs.microsoft.com/bs-latn-ba/azure/active-directory-b2c/b2clogin

I have added this change to the initialize function on our fork and verified that it works:
information-experience-sweden-ab@fdc6855