fix memory leak in z_declare_subscriber #1278

	#
	# Copyright (c) 2022 ZettaScale Technology
	#
	# This program and the accompanying materials are made available under the
	# terms of the Eclipse Public License 2.0 which is available at
	# http://www.eclipse.org/legal/epl-2.0, or the Apache License, Version 2.0
	# which is available at https://www.apache.org/licenses/LICENSE-2.0.
	#
	# SPDX-License-Identifier: EPL-2.0 OR Apache-2.0
	#
	# Contributors:
	# ZettaScale Zenoh Team, <[email protected]>
	#
	name: multicast

	on:
	push:
	branches: ["**"]
	pull_request:
	branches: ["**"]
	schedule:
	- cron: "0 6 * * 1-5"

	jobs:
	build:
	name: Build on macOS-latest
	runs-on: macOS-latest
	strategy:
	fail-fast: false
	matrix:
	os: [macOS-latest]

	steps:
	- uses: actions/checkout@v2

	- name: Compile debug
	run: make all
	env:
	BUILD_TYPE: Debug
	BUILD_TESTING: OFF
	BUILD_MULTICAST: ON
	BUILD_INTEGRATION: OFF
	ZENOH_BRANCH: master

	- name: Test debug
	run: make test
	env:
	ARGS: -V

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