test_kerberos_1_15_1 is broken (and we may need to fix the kerberos checker rather than the test)

Kerberos's data seems to have changed and it's affecting `test_kerberos_1_15_1`

Previously, you would get 
vendor: mit
product: kerberos
version: 1.15.1

But it seems like now we get
product: kerberos_5

I think we probably want the checker to return kerberos5 to match the database.

