Fix for RC4-HMAC encryption type has already been integrated via following RFE:
5093560: Add support for RC4 encryption type

On Windows, Java Kerberos provider uses LSA API is used to acquire the native TGT.
We check for the encryption types of the key obtained. Currently we only accept
DES. Now that support for RC4-HMAC is available, we should allow to accept
RC4-HMAC.