mountlib: fix mount --daemon not working with encrypted config - fixes #2473

This passes the configKey to the child process as an Obscured temporary file with an environment variable to the

cmd/mountlib/mount.go

@@ -10,6 +10,7 @@ import (
 
 	"github.com/ncw/rclone/cmd"
 	"github.com/ncw/rclone/fs"
+	"github.com/ncw/rclone/fs/config"
 	"github.com/ncw/rclone/fs/config/flags"
 	"github.com/ncw/rclone/vfs"
 	"github.com/ncw/rclone/vfs/vfsflags"
@@ -216,6 +217,11 @@ be copied to the vfs cache before opening with --vfs-cache-mode full.
 ` + vfs.Help,
 		Run: func(command *cobra.Command, args []string) {
 			cmd.CheckArgs(2, 2, command, args)
+
+			if Daemon {
+				config.PassConfigKeyForDaemonization = true
+			}
+
 			fdst := cmd.NewFsDir(args)
 
 			// Show stats if the user has specifically requested them