HADOOP-8719 may have been valid at some point, but since then the world has moved on
- nobody should be using Hadoop without Kerberos
- kerberos support on java 8 + macos works just fine
The clause to reset the java system properties is enough to stop kerberos working, even
when the user is kinited in.
Propose: remove/revert the changes. If people want it, they can set the options in HADOOP_CLIENT_OPTS