[fix] UnicodeEncodeError for preferences ULR

Closes: https://github.com/searxng/searxng/issues/166

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

searx/settings.yml

@@ -1456,7 +1456,7 @@ engines:
     timeout: 5.0
     disabled: true
 
-  - name: słownik języka polskiego
+  - name: slownik jezyka polskiego
     engine: sjp
     shortcut: sjp
     base_url: https://sjp.pwn.pl/