[fix] libgen.fun is down, switch to libgen.rs

Closes: https://github.com/searxng/searxng/issues/3178
Signed-off-by: Markus Heiser <markus.heiser@darmarit.de>

searx/settings.yml

@@ -1006,8 +1006,9 @@ engines:
 
   - name: library genesis
     engine: xpath
-    search_url: https://libgen.fun/search.php?req={query}
-    url_xpath: //a[contains(@href,"get.php?md5")]/@href
+    # search_url: https://libgen.is/search.php?req={query}
+    search_url: https://libgen.rs/search.php?req={query}
+    url_xpath: //a[contains(@href,"book/index.php?md5")]/@href
     title_xpath: //a[contains(@href,"book/")]/text()[1]
     content_xpath: //td/a[1][contains(@href,"=author")]/text()
     categories: files