lib/protocol: Fix yet another deadlock (fixes #5678) (#5679)
lib/protocol: Fix yet another deadlock (fixes #5678) (#5679)

* lib/protocol: Fix yet another deadlock (fixes #5678)

* more consistency

* read deadlock

* naming

* more naming

xduugu/syncthing,AudriusButkevicius/syncthing,syncthing/syncthing,xduugu/syncthing,syncthing/syncthing,AudriusButkevicius/syncthing,imsodin/syncthing,imsodin/syncthing,wweich/syncthing,syncthing/syncthing,xduugu/syncthing,syncthing/syncthing,syncthing/syncthing,wweich/syncthing,wweich/syncthing,imsodin/syncthing,wweich/syncthing,imsodin/syncthing,AudriusButkevicius/syncthing,xduugu/syncthing,imsodin/syncthing,syncthing/syncthing,AudriusButkevicius/syncthing