PIG-3512: Reducer estimater is broken by PIG-3497

git-svn-id: https://svn.apache.org/repos/asf/pig/branches/branch-0.12@1531438 13f79535-47bb-0310-9956-ffa450edef68
Move PIG-3510 to the right fix version

git-svn-id: https://svn.apache.org/repos/asf/pig/branches/branch-0.12@1531439 13f79535-47bb-0310-9956-ffa450edef68