[mod] Fix Libgen + Uncomment Ebay and Urbandictiorany (#2986)

- Change Libgen provider and use https by default.
- Umcomment Urbandictionary but disable it by default, it is working.
- Uncomment Ebay as it is working correctly.
(For ebay in the future: base_url should be changed from settings.yml  just like peertube or invidious)

searx/settings.yml

@@ -434,11 +434,11 @@ engines:
       require_api_key: false
       results: HTML
 
-#  - name : ebay
-#    engine : ebay
-#    shortcut : eb
-#    disabled : True
-#    timeout: 5
+  - name : ebay
+    engine : ebay
+    shortcut : eb
+    disabled : True
+    timeout: 5
 
   - name : 1x
     engine : www1x
@@ -730,9 +730,8 @@ engines:
     engine : xpath
     paging : True
     page_size : 25
-    enable_http: True
-    search_url : http://libgen.rs/search.php?req={query}&page={pageno}
-    url_xpath : //a[contains(@href,"bookfi.net/md5")]/@href
+    search_url : https://libgen.rs/search.php?req={query}&page={pageno}
+    url_xpath : //a[contains(@href,"library.lol/main")]/@href
     title_xpath : //a[contains(@href,"book/")]/text()[1]
     content_xpath : //td/a[1][contains(@href,"=author")]/text()
     categories : general, files
@@ -1182,14 +1181,15 @@ engines:
 #    base_url : https://uncyclopedia.wikia.com/
 #    number_of_results : 5
 
-# tmp suspended - too slow, too many errors
-#  - name : urbandictionary
-#    engine        : xpath
-#    search_url    : https://www.urbandictionary.com/define.php?term={query}
-#    url_xpath     : //*[@class="word"]/@href
-#    title_xpath   : //*[@class="def-header"]
-#    content_xpath : //*[@class="meaning"]
-#    shortcut : ud
+
+  - name : urbandictionary
+    engine        : xpath
+    search_url    : https://www.urbandictionary.com/define.php?term={query}
+    url_xpath     : //*[@class="word"]/@href
+    title_xpath   : //*[@class="def-header"]
+    content_xpath : //*[@class="meaning"]
+    shortcut : ud
+    disabled : True
 
   - name : unsplash
     engine : unsplash