cosmetic: reduce noise

test/610_proxy_wait_for_weave_test.sh

@@ -6,7 +6,7 @@ start_suite "Proxy waits for weave to be ready before running container commands
 weave_on $HOST1 launch-proxy
 BASE_IMAGE=busybox
 # Ensure the base image does not exist, so that it will be pulled
-if (docker_on $HOST1 images $BASE_IMAGE | grep $BASE_IMAGE); then
+if (docker_on $HOST1 images $BASE_IMAGE | grep -q $BASE_IMAGE); then
   docker_on $HOST1 rmi $BASE_IMAGE
 fi