Handle malformed Kmsi form field in ADFS

[dboitnot]

I've encountered a situation where the value for Kmsi is "true " (with trailing space). This leads to:

DEBU[0003] HTTP Req URL="https://<redacted>/adfs/ls/IdpInitiatedSignOn.aspx?loginToRp=urn%3Aamazon%3Awebservices&client-request-id=3b.." http=client method=POST
DEBU[0003] HTTP Res Status="500 Internal Server Error" http=client
unable to classify response from auth server

Apparently this value is being pulled directly from the server's response:

saml2aws/pkg/provider/adfs/adfs.go

Line 75 in df3f6cf

authForm := url.Values{}

[dboitnot]

It turns out that, at least in my case, it's not trailing white space but a second, empty value for Kmsi in the form:

len(authForm["Kmsi"]) // == 2

[christianmeyer]

Just out of curiosity, is that issue also persisting with the version out of #795 ? In that case I would adopt the referenced fix.