actions from subworkflows that use oozie.libpath have duplicate classpath

OOZIE-564 as 2 commits, the second commit (git-svn-id: https://svn.apache.org/repos/asf/incubator/oozie/trunk@1179035 13f79535-47bb-0310-9956-ffa450edef68) seems to be incorrectly re-append the oozie.libpath resolved classpath to subworkflows.

reverting that chance fixes the problem and it does not seem to break anything else.