In case in the root tree there are only OU and any USER, then the ad test button will report this. It is better to use a subtree scope so we actually look inside OUs.
Code changed in jenkins
User: Felix Belzunce Arcos
Merge pull request #31 from fbelzunc/JENKINS-34444
[FIXED JENKINS-34444] Test button is reporting managerDN binding is successful but was not able to find any user on the tree