[mod] disbale engine tineye by default

Tineye becomes active as soon as a https:// signature is found in the search
term, but most of the time a reverse image search is not requested when a URL is
specified, often the URL is just from a C&P.

The frequent requests to tineye lead in the end to the SearXNG instance being
blocked by tineye and the user seeing unexpected error messages.

BTW: many maintainers have disabled this engine in their local SearXNG settings.

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