Ensure silent background execution (#388)

Author: shikokuchuo

R/daemon.R

@@ -110,14 +110,6 @@ daemon <- function(
     devnull <- file(nullfile(), open = "w", blocking = FALSE)
     sink(file = devnull)
     sink(file = devnull, type = "message")
-    on.exit(
-      {
-        sink(type = "message")
-        sink()
-        close(devnull)
-      },
-      add = TRUE
-    )
   }
   xc <- 0L
   task <- 1L