check for acpi before getting lid state

.config/sway/scripts/clamshell.sh

@@ -1,6 +1,8 @@
 #!/usr/bin/bash
-if cat /proc/acpi/button/lid/*/state | grep -q open; then
+if [-d "/proc/acpi" ]; then
+  if cat /proc/acpi/button/lid/*/state | grep -q open; then
      swaymsg output eDP-1 enable
-else
+  else
      swaymsg output eDP-1 disable
+  fi
 fi