[mod] online engines - set common HTTP headers

The online engines emulate a request as it would come from a web browser, which
is why the HTTP headers in the default settings should also be set the way a
standard web browser would set them.

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

searx/engines/duckduckgo_weather.py

@@ -27,8 +27,6 @@ about = {
     "results": "JSON",
 }
 
-send_accept_language_header = True
-
 # engine dependent config
 categories = ["weather"]
 base_url = "https://duckduckgo.com/js/spice/forecast/{query}/{lang}"