upgrade ivy to 2.5.3 (CVE fixes)

build.xml

@@ -60,7 +60,7 @@
   <target name="install-ivy" description="--> install ivy">
     <local name="ivy.download.dir"/><property name="ivy.download.dir" value="${basedir}/ivy" />
     <local name="ivy.download.file"/><property name="ivy.download.file" value="${ivy.download.dir}/ivy.jar" />
-    <local name="ivy.download.version"/><property name="ivy.install.version" value="2.5.0"/>
+    <local name="ivy.download.version"/><property name="ivy.install.version" value="2.5.3"/>
     <local name="ivy.debian.file"/><property name="ivy.debian.file" value="/usr/share/java/ivy.jar" />
 
     <!-- Check whether ivy is already available as a Debian package -->