all: Typos

Skip-check: authors

GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/4263

cmd/syncthing/main.go

@@ -1074,7 +1074,7 @@ func setupGUI(mainService *suture.Supervisor, cfg *config.Wrapper, m *model.Mode
 
 	if cfg.Options().StartBrowser && !runtimeOptions.noBrowser && !runtimeOptions.stRestarting {
 		// Can potentially block if the utility we are invoking doesn't
-		// fork, and just execs, hence keep it in it's own routine.
+		// fork, and just execs, hence keep it in its own routine.
 		<-api.startedOnce
 		go openURL(guiCfg.URL())
 	}