[fix] engine: wikicommons - don't quoute ':|' in URL parameters

From [1]: It seems to be because of [2] For some reason it gets url encoded
twice, resulting in

- ``filetype%253Abitmap%257Cdrawing+birds`` instead of
- ``filetype:bitmap%7Cdrawing+birds``

[1] https://github.com/searxng/searxng/issues/2707
[2] https://github.com/searxng/searxng/blob/master/searx/engines/wikicommons.py#L43



Closes: #2707
Signed-off-by: Markus Heiser <markus.heiser@darmarit.de>