[mod] fetch supported languages for several engines

utils/fetch_languages.py gets languages supported by each engine and
generates engines_languages.json with each engine's supported language.

searx/engines/mediawiki.py

@@ -15,7 +15,6 @@
 from json import loads
 from string import Formatter
 from urllib import urlencode, quote
-from searx.engines.wikipedia import supported_languages
 
 # engine dependent config
 categories = ['general']