Adsurl to url (#2861)

* move adsurl field to url field when fetching with ADS fetcher.

* Update CHANGELOG.md

* Update AstrophysicsDataSystem.java

use FieldName.URL instead of "url" as commented by @tobiasdiez

CHANGELOG.md

@@ -11,6 +11,7 @@ We refer to [GitHub issues](https://github.com/JabRef/jabref/issues) by using `#
 ## [Unreleased]
 
 ### Changed
+- We moved the `adsurl` field to `url` field when fetching with the ADS fetcher. 
 - We continued to improve the new groups interface:
   - You can now again select multiple groups (and a few related settings were added to the preferences) [#2786](https://github.com/JabRef/jabref/issues/2786).
   - We further improved performance of group operations, especially of the new filter feature [#2852](https://github.com/JabRef/jabref/issues/2852). 

src/main/java/org/jabref/logic/importer/fetcher/AstrophysicsDataSystem.java

@@ -10,6 +10,7 @@
 import java.util.List;
 import java.util.Objects;
 
+import org.jabref.logic.cleanup.MoveFieldCleanup;
 import org.jabref.logic.formatter.bibtexfields.ClearFormatter;
 import org.jabref.logic.formatter.bibtexfields.NormalizeNamesFormatter;
 import org.jabref.logic.formatter.bibtexfields.RemoveBracesFormatter;
@@ -154,8 +155,9 @@ public void doPostCleanup(BibEntry entry) {
         new FieldFormatterCleanup(FieldName.TITLE, new RemoveBracesFormatter()).cleanup(entry);
         new FieldFormatterCleanup(FieldName.AUTHOR, new NormalizeNamesFormatter()).cleanup(entry);
 
-        // Remove url to ADS page
+        // Remove ADS note
         new FieldFormatterCleanup("adsnote", new ClearFormatter()).cleanup(entry);
-        new FieldFormatterCleanup("adsurl", new ClearFormatter()).cleanup(entry);
+        // Move adsurl to url field
+        new MoveFieldCleanup("adsurl", FieldName.URL).cleanup(entry);
     }
 }