Update apache karaf to version 4.2.3

Change-Id: If9aadfa2715a3f100df6e34e25789e74399759a0
diff --git a/tools/package/bin/onos-backup b/tools/package/bin/onos-backup
index 5082957..dc1bff5 100755
--- a/tools/package/bin/onos-backup
+++ b/tools/package/bin/onos-backup
@@ -5,7 +5,7 @@
 
 ONOS_HOME=${ONOS_HOME:-$(cd $(dirname $0)/.. >/dev/null 2>&1 && pwd)}
 ONOS_DEFAULT_ARCHIVE=$(dirname $ONOS_HOME)/onos-data.tar.gz
-ONOS_KARAF=$ONOS_HOME/apache-karaf-4.2.2
+ONOS_KARAF=$ONOS_HOME/apache-karaf-4.2.3
 
 # Fetch the name of the archive or use a default if none is specified
 archive=${1:-$ONOS_DEFAULT_ARCHIVE}