[fix] Gigablast.com has been erased

[1] https://www.reddit.com/r/searchengines/comments/128wdcp/gigablastcom_has_been_erased/

Closes: https://github.com/searxng/searxng/issues/2321
Signed-off-by: Markus Heiser <markus.heiser@darmarit.de>

searx/settings.yml

@@ -670,17 +670,6 @@ engines:
     engine: genius
     shortcut: gen
 
-  - name: gigablast
-    engine: gigablast
-    shortcut: gb
-    timeout: 4.0
-    # API key required, see https://gigablast.com/searchfeed.html
-    # gb_userid: unset
-    # gb_code: unknown
-    disabled: true
-    additional_tests:
-      rosebud: *test_rosebud
-
   - name: gentoo
     engine: gentoo
     shortcut: ge