dynamicdns: Fix file creation with update URL
dynamicdns: Fix file creation with update URL

The wget command to push the current IP via update URL will download the
update URL document without deleting the HTML document afterwards. This
will cause the script to flood "/root/" folder.

vignanl/Plinth,harry-7/Plinth,harry-7/Plinth,vignanl/Plinth,kkampardi/Plinth,vignanl/Plinth,freedomboxtwh/Plinth,kkampardi/Plinth,kkampardi/Plinth,kkampardi/Plinth,vignanl/Plinth,harry-7/Plinth,kkampardi/Plinth,freedomboxtwh/Plinth,freedomboxtwh/Plinth,freedomboxtwh/Plinth,harry-7/Plinth,freedomboxtwh/Plinth,harry-7/Plinth,vignanl/Plinth