[X] Correctly detect laptop or desktop for key map

While shellcheck complains that posix does not know about HOSTNAME
env var, it seems to be required for zsh/bash.

X/.config/xresources/xinitrc

@@ -36,10 +36,11 @@ fi
 setxkbmap -option ctrl:nocaps
 # sets default to EURkey layout, with possibility to switch to german
 # sets german layout to be default for the only pc I have with a german keyboard
-if [ "$HOST" = "marty-desk" ]; then
-  setxkbmap -layout de,eu
-else
+# shellcheck disable=2039
+if [ "$HOST" = "lidell" ] || [ "$HOSTNAME" = "lidell" ]; then
   setxkbmap -layout eu,de
+else
+  setxkbmap -layout de,eu
 fi
 # allows switching layouts with alt+space
 setxkbmap -option grp:alt_shift_toggle