[FIXED JENKINS-8159] switch to default-jre

Eclipse package depends on this
<http://packages.ubuntu.com/maverick/eclipse-jdt>, so I'm doing
monkey-see-monkey-do.

changelog.html

@@ -49,6 +49,9 @@ Upcoming changes</a>
   <li class=bug>
     Debian package no longer messes around with the file permissions
     (<a href="http://issues.jenkins-ci.org/browse/JENKINS-4047">issue 4047</a>)
+  <li class=bug>
+    Fixed a JVM dependency in debian package so that it can run with OpenJDK
+    (<a href="http://issues.jenkins-ci.org/browse/JENKINS-8159">issue 8159</a>)
 </ul>
 </div><!--=TRUNK-END=-->
 

debian/debian/control

@@ -8,7 +8,7 @@ Homepage: https://jenkins-ci.org/
 
 Package: jenkins
 Architecture: all
-Depends: ${shlibs:Depends}, ${misc:Depends}, daemon, adduser, java-virtual-machine, java2-runtime, psmisc
+Depends: ${shlibs:Depends}, ${misc:Depends}, daemon, adduser, psmisc, default-jre
 Conflicts: hudson
 Replaces: hudson
 Description: Continuous integration system written in Java