Optimize the Authentication Exception in ClientService.java

[prb112]

When using the BasicEndpoint with an invalid password, the user receives a ClientServiceException.
ClientService Exception on Line 1317.
1 - The Response Code on 1316 should be checked to see if it's 401 before forceAuthentication
(Else it's possible you get an error)
2 - Throw an AuthenticationException specific to the ClientServices and not wrapped in a generic ClientServicesException.

• or -
  3 - Add a message to the AuthenticationException that indicates the issue

[prb112]

Rajmeet completed this pull request