HBASE-16367 Race between master and region server initialization may lead to premature server abort - addendum shortens the waiting duration

hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/HRegionServer.java

@@ -819,7 +819,7 @@ public class HRegionServer extends HasThread implements
     blockAndCheckIfStopped(this.clusterStatusTracker);
 
     if (this.initLatch != null) {
-      this.initLatch.await(50, TimeUnit.SECONDS);
+      this.initLatch.await(20, TimeUnit.SECONDS);
     }
     // Retrieve clusterId
     // Since cluster status is now up