Clean up RTC_C_EXPORT in cpp file #1122

	name: Build without media
	on:
	push:
	branches:
	- master
	pull_request:
	jobs:
	build-nomedia:
	runs-on: ubuntu-latest
	steps:
	- uses: actions/checkout@v2
	- name: install packages
	run: sudo apt update && sudo apt install libssl-dev
	- name: submodules
	run: git submodule update --init --recursive --depth 1
	- name: cmake
	run: cmake -B build -DUSE_GNUTLS=0 -DNO_MEDIA=1 -DWARNINGS_AS_ERRORS=1
	- name: make
	run: (cd build; make -j2)
	- name: test
	run: ./build/tests
	build-nomedia-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 -DNO_MEDIA=1 -DWARNINGS_AS_ERRORS=1
	- name: nmake
	run: \|
	cd build
	set CL=/MP
	nmake
	- name: test
	run: \|
	cd build
	./tests

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