Fix crash in negotiationNeeded() when track is destroyed #2765

	name: Build with OpenSSL
	on:
	push:
	branches:
	- master
	pull_request:
	jobs:
	build-linux:
	runs-on: ubuntu-latest
	steps:
	- uses: actions/checkout@v2
	- name: install packages
	run: sudo apt update && sudo apt install libssl-dev libsrtp2-dev
	- name: submodules
	run: git submodule update --init --recursive --depth 1
	- name: cmake
	run: cmake -B build -DUSE_GNUTLS=0 -DUSE_SYSTEM_SRTP=1 -DWARNINGS_AS_ERRORS=1
	- name: make
	run: (cd build; make -j2)
	- name: test
	run: ./build/tests
	build-macos:
	runs-on: macos-latest
	steps:
	- uses: actions/checkout@v2
	- name: install packages
	run: HOMEBREW_NO_INSTALL_CLEANUP=1 brew reinstall openssl@3
	- name: submodules
	run: git submodule update --init --recursive --depth 1
	- name: cmake
	run: cmake -B build -DUSE_GNUTLS=0 -WARNINGS_AS_ERRORS=1 -DENABLE_LOCAL_ADDRESS_TRANSLATION=1
	env:
	OPENSSL_ROOT_DIR: /usr/local/opt/[email protected]
	- name: make
	run: (cd build; make -j2)
	- name: test
	run: ./build/tests
	build-windows:
	runs-on: windows-latest
	steps:
	- uses: actions/checkout@v2
	- uses: ilammy/msvc-dev-cmd@v1
	- name: install packages
	run: choco install openssl --version=3.1.1
	- name: submodules
	run: git submodule update --init --recursive --depth 1
	- name: cmake
	run: cmake -B build -G "NMake Makefiles" -DUSE_GNUTLS=0 -DWARNINGS_AS_ERRORS=1
	- name: nmake
	run: \|
	cd build
	set CL=/MP
	nmake
	- name: test
	run: \|
	cd build
	./tests

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