upgrade httpclient version

Signed-off-by: olivier lamy <olamy@apache.org>

pom.xml

@@ -86,8 +86,8 @@
 
     <cxf.version>3.0.3</cxf.version>
     <derbyVersion>10.10.1.1</derbyVersion>
-    <httpclient.version>4.3.6</httpclient.version>
-    <httpclient.core.version>4.4</httpclient.core.version>
+    <httpclient.version>4.5.2</httpclient.version>
+    <httpclient.core.version>4.4.4</httpclient.core.version>
     <javaxMailVersion>1.4</javaxMailVersion>
     <jettyVersion>8.1.14.v20131031</jettyVersion>
     <guava.version>16.0.1</guava.version>