Add workaround for javadoc verify jobs

Nexus unpack plugin throws a "504 gateway timeout" for jobs archiving
large number of small files. Remove the workaround only we move away
from using Nexus as the log server.

Tested the workaround with javadoc-verify job.
https://logs.opendaylight.org/releng/vex-yul-odl-jenkins-1/bgpcep-maven-javadoc-verify-sodium-openjdk8/189

Issue: IT-16635
Change-Id: Ic7b0e3a56800312e3bcb888b4d35f9ccfd2d5018
Signed-off-by: Anil Belur <abelur@linuxfoundation.org>