AMBARI-20745 : Metrics collector goes down after starting up. (avijayan)

ambari-metrics/ambari-metrics-timelineservice/pom.xml

@@ -477,7 +477,7 @@
     <dependency>
       <groupId>org.apache.httpcomponents</groupId>
       <artifactId>httpclient</artifactId>
-      <version>4.2.5</version>
+      <version>4.5.2</version>
     </dependency>
     <dependency>
       <groupId>com.google.guava</groupId>