Description of problem:
Error message for user-mod --rename with an empty string is "internal error has
occurred".

Version-Release number of selected component (if applicable):
ipa-server-2.2.0-9.el6

How reproducible:


Steps to Reproduce:

:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
:
:: [   LOG    ] :: ipa-user-cli-mod-064: Rename user with empty string.
:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
:

:: [   LOG    ] :: Executing: ipa user-mod --rename= crazylast3344
:: [   LOG    ] :: "ipa user-mod --rename= crazylast3344" failed as expected.
:: [   FAIL   ] :: ERROR: Message not as expected. GOT: ipa: ERROR: an internal
error has occurred  EXP: ipa: ERROR: invalid 'rename': can't be empty
:: [   FAIL   ] :: Verify expected error message for empty string (Expected 0,
got 1)
:: [   LOG    ] :: Duration: 12s
:: [   LOG    ] :: Assertions: 0 good, 2 bad
:: [   FAIL   ] :: RESULT: ipa-user-cli-mod-064: Rename user with empty string.


Actual results:
ipa: ERROR: an internal error has occurred

Expected results:
ipa: ERROR: invalid 'rename': can't be empty

Additional info: