webui: fixes normalization of value in attributes widget
Fix is in checkboxes widget but the only affected one is attributes widget.
Reproduction:
1. Add permission with attribute with uppercase character
$ ipa permission-add aa_test --type=stageuser --attrs=businessCategory --right=read
2. Check if it is correctly displayed in Web UI
Actual result:
- businesscategory is not checked
Expected result:
- businesscategory is checked
Reviewed-By: Pavel Vomacka <pvomacka@redhat.com>