Sign sync issue when directory_group names have upper-case letters and adobe console is source

[Luci2015]

Description
Sign sync issue when directory_group names have upper-case letters and adobe console is source.
What happens is that groups are not found in Admin Console because of the case sensitivity

Steps to reproduce

• set up an admin_console source for Sign sync
• set up directory_group mapping to have upper-case letters in the config file and in Admin Console
• run Sign sync as usual

Expected behavior
groups should be found

Environment

• UST version: 2.9.0rc1 and up
• OS type and version: all
• Any other relevant info: 2.8.0 works because the directory_adobe_console.py worked on a different logic to iterate through AC groups.