Update apache karaf to version 4.2.3

Change-Id: If9aadfa2715a3f100df6e34e25789e74399759a0
diff --git a/tools/build/envDefaults b/tools/build/envDefaults
index 70b294d..3f23719 100644
--- a/tools/build/envDefaults
+++ b/tools/build/envDefaults
@@ -5,7 +5,7 @@
 
 # M2 repository and Karaf gold bits
 export M2_REPO=${M2_REPO:-~/.m2/repository}
-export KARAF_VERSION=4.2.2
+export KARAF_VERSION=4.2.3
 export KARAF_ZIP=${KARAF_ZIP:-~/Downloads/apache-karaf-$KARAF_VERSION.zip}
 export KARAF_TAR=${KARAF_TAR:-~/Downloads/apache-karaf-$KARAF_VERSION.tar.gz}
 export KARAF_DIST=$(basename $KARAF_ZIP .zip)