suppress warning by karaf client

Change-Id: I175210e76d2b8085f4165eac00785f30bef0fd89
diff --git a/tools/test/bin/onos b/tools/test/bin/onos
index a0c126c..b18bae8 100755
--- a/tools/test/bin/onos
+++ b/tools/test/bin/onos
@@ -10,4 +10,5 @@
 [ "$1" = "-w" ] && shift && onos-wait-for-start $1
 
 [ -n "$1" ] && OCI=$(find_node $1) && shift
+unset KARAF_HOME
 client -h $OCI -u karaf "$@" 2>/dev/null