Description of problem:
Customer said that they migrated users from the older version of IPA that had
"objectclass=posixAccount" rather than "objectclass=posixaccount, which is
problematic when comes to using "ipa idoverrideuser-add"

Version-Release number of selected component (if applicable):
ipa-server-4.4.0-14.el7_3.7.x86_64
389-ds-base-1.3.5.10-20.el7_3.x86_64


How reproducible:


Steps to Reproduce:
1. Create two users in IPA using a ldif file, one with
""objectclass=posixAccount" and the other with "objectclass=posixAccount"
2. Load the users to the IPA
3. Then run:
ipa idview-add testview
ipa idoverrideuser-add testview <username> --homeDirectory=/var/tmp

Actual results:

user with "objectClass: posixAccount"
# ipa idoverrideuser-add testview cgoodwin --homedir=/home/cgoodwin
ipa: ERROR: invalid 'IPA object': system IPA objects (e.g system groups, user
private groups) cannot be overridden


user with "objectClass: posixaccount
# ipa idoverrideuser-add testview bgoodwin --homedir=/home/mygoodwin
---------------------------------
Added User ID override "bgoodwin"
---------------------------------
  Anchor to override: bgoodwin
  Home directory: /home/mygoodwin


Expected results:


Additional info:
The workaround is to replace "objectclass=posixAccount" with
"objectclass=posixaccount