Merge branch '2021.03-rc' into copyright-2021

diff --cc src/Core/Config/JitConfig.php
Simple merge

diff --cc src/Core/Config/PreloadConfig.php
Simple merge

diff --cc src/Core/Installer.php
Simple merge

diff --cc src/Module/Invite.php
Simple merge

diff --cc src/Protocol/ActivityPub/Transmitter.php
Simple merge

diff --cc src/Util/Logger/AbstractLogger.php
Simple merge

diff --cc src/Util/Logger/StreamLogger.php
Simple merge

diff --cc src/Util/Logger/SyslogLogger.php
Simple merge

diff --cc src/Util/ParseUrl.php
Simple merge

diff --cc tests/src/Core/Config/CacheTest.php
Simple merge

diff --cc tests/src/Core/Config/ConfigTest.php
Simple merge

diff --cc tests/src/Core/Config/JitConfigTest.php
Simple merge

diff --cc tests/src/Core/Config/PreloadConfigTest.php
Simple merge

diff --cc tests/src/Util/Logger/AbstractLoggerTest.php
Simple merge

diff --cc view/lang/C/messages.po
Simple merge

diff --cc view/lang/hu/messages.po
Simple merge

diff --cc view/lang/it/messages.po
Simple merge

diff --cc view/lang/ru/messages.po
Simple merge