Fix Access Key requests (#11979)

Fix accessing claims when auth error is unchecked.

Only replaced when unchecked and when clearly without side effects.

Fixes #11959

cmd/jwt/parser.go

@@ -81,6 +81,15 @@ type MapClaims struct {
 	jwtgo.MapClaims
 }
 
+// GetAccessKey will return the access key.
+// If nil an empty string will be returned.
+func (c *MapClaims) GetAccessKey() string {
+	if c == nil {
+		return ""
+	}
+	return c.AccessKey
+}
+
 // NewStandardClaims - initializes standard claims
 func NewStandardClaims() *StandardClaims {
 	return &StandardClaims{}