Small fix (coscine/issues#1035)

src/Database/Models/ResourceModel.cs

@@ -178,7 +178,7 @@ namespace Coscine.Database.Models
             var projectId = new ProjectResourceModel().GetProjectForResource(resource.Id);
             IEnumerable<string> allowedAccessLabels = allowedAccess.Select(x => x.ToLower().Trim()).ToList();
             return DatabaseConnection.ConnectToDatabase((db) => (from relation in db.ProjectRoles
-                                                                  where relation.ProjectId != projectId
+                                                                  where relation.ProjectId == projectId
                                                                       && relation.User.Id == user.Id
                                                                       && allowedAccessLabels.Contains(relation.Role.DisplayName.ToLower())
                                                                   select relation).Any());