Make sure `build.properties' is honored.

--- jde/build.xml
+++ jde/build.xml
@@ -14,6 +14,7 @@
   <property name="project.version" value="2.4.0"/>
   <property name="config.dir" location="./config"/>
 
+  <property file="build.properties"/>
 
   <!-- everything depends on this initialization target -->
   <target name="init">
