torrentscsv: site no longer accepts empty search query

so we supply an * instead.

src/Jackett.Common/Indexers/Torrentscsv.cs

@@ -70,6 +70,7 @@ namespace Jackett.Common.Indexers {
         public async Task<IEnumerable<ReleaseInfo>> PerformQuery (TorznabQuery query, int attempts) {
             var releases = new List<ReleaseInfo> ();
             var searchString = query.GetQueryString ();
+            if (string.IsNullOrEmpty(searchString)) searchString = "*";
 
             var queryCollection = new NameValueCollection ();