Description of problem:
external auth(httpd): two factor authentication with user password and otp fails.


Version-Release number of selected component (if applicable):
5.6.1.0.20160726144018_810a94f

How reproducible:
always.

Steps to Reproduce:
1. Configure CFME Administrative UI for external auth(httpd)
2. Configure External Authentication from appliance_console
3. Enabling 2-Factor Authentication for user in IPA server. 
4. create/retrieve ldap user group in the CFME.
4. Try to login with username, and password + OTP. observe that login (auth) fails.
5. The user login with password+OTP works fine for IPA login.
6. observe that there is conflicting log messages in CFME audit.log & evm.log


[root@cfmeappliancesaxpxin log]# tail -f evm.log| grep ldaptest
[----] I, [2016-08-04T10:41:36.759965 #16920:1403084]  INFO -- : <AuditSuccess> MIQ(Authenticator.authenticate) userid: [ldaptest] - User ldaptest successfully validated by External httpd
[----] I, [2016-08-04T10:41:36.919721 #16920:1403084]  INFO -- : MIQ(Authenticator::Httpd#authorize) Authorized User: [ldaptest]
[----] I, [2016-08-04T10:41:37.017044 #16920:1403084]  INFO -- : <AuditSuccess> MIQ(Authenticator.authenticate) userid: [ldaptest] - Authentication successful for user ldaptest
[----] W, [2016-08-04T10:41:37.880881 #16901:1404718]  WARN -- : <AuditFailure> MIQ(Authenticator.authenticate) userid: [ldaptest] - Authentication failed for userid ldaptest: Failure setting user credentials

Actual results:
two factor authentication with user password and otp fails.

Expected results:
two factor authentication with username, (password+OTP) is expected to work.

Additional info:
1. the user login works fine with "user authentication type" option in IPA set to "password"
2. http://file.rdu.redhat.com/abellott/manageiq_docs/master/auth/ipa_2fa.html
3. screenshot(ipa_user_two_factor_auth) for user configuration in IPA is attached.