KerberosTokenTest testKerberosViaCustomTokenAction should not run on IBM Java

KerberosTokenTest testKerberosViaCustomTokenAction should not run on IBM Java.

The test case fails on ClassNotFound com.ibm.security.jgss.InquireType - this is thrown due to wss4j-ws-security-common having a hard coded check for IBM Java to use the above mentioned class. 

KerberosClientExceptionAction.class:
`
try{}{ {}
{{ Class inquireType = Class.forName(IS_IBM_VENDOR ? "com.ibm.security.jgss.InquireType" : "com.sun.security.jgss.InquireType"); }}
{{ Class extendedGSSContext = Class.forName(IS_IBM_VENDOR ? "com.ibm.security.jgss.ExtendedGSSContext" : "com.sun.security.jgss.ExtendedGSSContext"); }}
{{ Method inquireSecContext = extendedGSSContext.getMethod("inquireSecContext", inquireType); }}
{{ Key key = (Key)inquireSecContext.invoke(secContext, Enum.valueOf(inquireType, "KRB5_GET_SESSION_KEY"));  krbCtx.setSecretKey(key); }}
{{ return krbCtx; }}
} }}{{{}catch (NoSuchMethodException | IllegalAccessException | InvocationTargetException | ClassNotFoundException var13){}{ {}
{{ throw new WSSecurityException(ErrorCode.FAILURE, var13, "kerberosServiceTicketError"); }}
}

`

Most of the test cases in KerberosTokenTest are set to avoid running when on IBM, I believe this test case should also be set to not run. A future improvement would be to update wss4j-ws-security-common to be IBM Semeru friendly, then update CXF accordingly.