Fix test invocation of weave again

Previous fix in b4a43f1b85 did not work
when built with code coverage.

Running a test script with -v causes `weave_on` to output progress
messages, so we don't want to use those commands inside `$()`

test/830_cni_plugin_test.sh

@@ -65,7 +65,7 @@ assert_raises "exec_on $HOST1 c1 $PING $C3IP"
 stop_weave_on $HOST1
 
 # Ensure no warning is printed to the standard error:
-ACTUAL_OUTPUT=$($SSH $HOST1 CHECKPOINT_DISABLE="$CHECKPOINT_DISABLE" weave launch-router 2>&1)
+ACTUAL_OUTPUT=$(CHECKPOINT_DISABLE="$CHECKPOINT_DISABLE" DOCKER_HOST=tcp://$HOST1:$DOCKER_PORT $WEAVE launch-router 2>&1)
 EXPECTED_OUTPUT=$($SSH $HOST1 docker inspect --format="{{.Id}}" weave)
 
 assert_raises "[ $EXPECTED_OUTPUT == $ACTUAL_OUTPUT ]"