Add note on rpc configurations

git-svn-id: https://svn.apache.org/repos/asf/hbase/trunk@1477858 13f79535-47bb-0310-9956-ffa450edef68
HBASE-8468 IntegrationTestImportTsv fails on a cluster

git-svn-id: https://svn.apache.org/repos/asf/hbase/trunk@1477877 13f79535-47bb-0310-9956-ffa450edef68