Revert "Use path relative to -bash"

This reverts commit 385a35a1.

postinstall_reseau.sh

@@ -29,5 +29,5 @@ git clone https://gitlab.tetras-libre.fr/tetras-libre/eole-wol
 chown -R www-data:www-data eole-wol/wol/www
 
 mkdir -p /etc/xrdp
-cp $DIR/wol/xrdp.ini /etc/xrdp/
+cp /var/www/eole-wol/wol/xrdp.ini /etc/xrdp
 systemctl restart xrdp