fix: update get method in Admin API to handle third parameter for settings retrieval #11639

This was wrongly requesting the setting, using the language parameter as the default value if not configured.

Author: poikilotherm

src/main/java/edu/harvard/iq/dataverse/api/Admin.java

@@ -281,7 +281,7 @@ public Response getSetting(@PathParam("name") String name, @PathParam("lang") St
             SettingsServiceBean.validateSettingName(name);
             SettingsServiceBean.validateSettingLang(lang);
 
-            String content = settingsSvc.get(name, lang);
+            String content = settingsSvc.get(name, lang, null);
             return (content != null) ? ok(content) : notFound("Setting " + name + " for language " + lang + " not found.");
         } catch (IllegalArgumentException iae) {
             return error(Response.Status.BAD_REQUEST, iae.getMessage());