Fix duplicate content.

src/Squidex.Domain.Apps.Entities/Contents/ContentQueryService.cs

@@ -129,12 +129,14 @@ namespace Squidex.Domain.Apps.Entities.Contents
                     yield return contentResult;
                 }
             }
-
+            else
+            {
                 foreach (var content in contents)
                 {
                     yield return content;
                 }
             }
+        }
 
         private ODataUriParser ParseQuery(IAppEntity app, string query, ISchemaEntity schema)
         {