HTTPASYNC-58: upgraded HttpClient to version 4.3.1

git-svn-id: https://svn.apache.org/repos/asf/httpcomponents/httpasyncclient/trunk@1533205 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/pom.xml b/pom.xml
index 59e1d17..b3939f9 100644
--- a/pom.xml
+++ b/pom.xml
@@ -66,7 +66,7 @@
 
   <properties>
     <httpcore.version>4.3</httpcore.version>
-    <httpclient.version>4.3</httpclient.version>
+    <httpclient.version>4.3.1</httpclient.version>
     <commons-logging.version>1.1.3</commons-logging.version>
     <!-- Note IO 2.3+ requires Java 6 -->
     <commons-io.version>2.2</commons-io.version>