[fix] make targets engines.languages and useragents.update

Since [PR 2600] is merged the update scripts for languages and useragent has
been moved to folder:

    searx_extra/update/

[PR 2600] https://github.com/searx/searx/pull/2600



Signed-off-by: Markus Heiser <markus.heiser@darmarit.de>