Updating Apache Karaf to 4.2.2.

Change-Id: I346f21b8da7583c77e7b0612c7f2931aa63a67e0
diff --git a/tools/package/onos-prep-karaf b/tools/package/onos-prep-karaf
index 468494f..4b845a6 100755
--- a/tools/package/onos-prep-karaf
+++ b/tools/package/onos-prep-karaf
@@ -12,7 +12,7 @@
 KARAF_PATCHES=$5
 SANDBOX=${6:-.}
 
-KARAF_VERSION="4.2.1"
+KARAF_VERSION="4.2.2"
 ONOS_SECURITY_MODE="false"
 
 PREFIX="onos-$ONOS_VERSION"