upgrade Ivy
diff --git a/build.properties b/build.properties
index c0fde72..20e9f47 100644
--- a/build.properties
+++ b/build.properties
@@ -17,7 +17,7 @@
 # Common properties. Could be overwritten by the concrete antlib project.
 
 # Ivy installation. Which version to use, where to store.
-ivy.install.version=2.4.0-rc1
+ivy.install.version=2.4.0
 ivy.jar.dir=${basedir}/ivy
 ivy.jar.file=${ivy.jar.dir}/ivy.jar