Update: Remove old metadata structure traces

coscine/issues#2462

src/Tree/Controllers/TreeController.cs

@@ -40,7 +40,6 @@ namespace Coscine.Api.Tree.Controllers
         private readonly ProjectResourceModel _projectResourceModel;
         private readonly CoscineLogger _coscineLogger;
         private readonly string _blobApiLink;
-        private readonly string _prefix;
         private readonly IConfiguration _configuration;
         private readonly string _shaclPropertyUrl = "http://www.w3.org/ns/shacl#property";
 
@@ -63,8 +62,7 @@ namespace Coscine.Api.Tree.Controllers
             var host = rule["Host:".Length..rule.IndexOf(";")];
             var path = rule[rule.IndexOf("/")..];
             _blobApiLink = $"https://{host}{path}/blob/";
-            _prefix = _configuration.GetStringAndWait("coscine/global/epic/prefix");
-            _coscineLDPHelper = new CoscineLDPHelper(_rdfStoreConnector, _prefix);
+            _coscineLDPHelper = new CoscineLDPHelper(_rdfStoreConnector);
         }
 
         /// <summary>