Merge r1599115 from trunk: YARN-2103. Inconsistency between viaProto flag and initial value of SerializedExceptionProto.Builder (Contributed by Binglin Chang)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1599121 13f79535-47bb-0310-9956-ffa450edef68