cmd/syncthing: Correct type assertion in verboseService (fixes #5270) (#5272)

cmd/syncthing/verboseservice.go

@@ -105,7 +105,7 @@ func (s *verboseService) formatEvent(ev events.Event) string {
 		return fmt.Sprintf("Device %v sent an index update for %q with %d items", data["device"], data["folder"], data["items"])
 
 	case events.DeviceRejected:
-		data := ev.Data.(map[string]interface{})
+		data := ev.Data.(map[string]string)
 		return fmt.Sprintf("Rejected connection from device %v at %v", data["device"], data["address"])
 
 	case events.FolderRejected: