Update apache karaf to version 4.2.3

Change-Id: If9aadfa2715a3f100df6e34e25789e74399759a0
diff --git a/tools/package/deb/prerm b/tools/package/deb/prerm
index d14f582..9d3aa62 100755
--- a/tools/package/deb/prerm
+++ b/tools/package/deb/prerm
@@ -14,7 +14,7 @@
 
 # Clean up onos runtime directories
 #      TODO don't hardcode karaf version
-rm -rf /opt/onos/apache-karaf-4.2.2/
+rm -rf /opt/onos/apache-karaf-4.2.3/
 rm -rf /opt/onos/var/*
 rm -rf /opt/onos/config
 rm -rf /opt/onos/options