Throw on search error

Fixes #4690

src/NzbDrone.Core/DecisionEngine/DownloadDecisionMaker.cs

@@ -70,6 +70,7 @@ namespace NzbDrone.Core.DecisionEngine
             {
                 DownloadDecision decision = null;
                 _logger.ProgressTrace("Processing release {0}/{1}", reportNumber, reports.Count);
+                _logger.Debug("Processing release '{0}' from '{1}'", report.Title, report.Indexer);
 
                 try
                 {

src/Radarr.Api.V3/Indexers/ReleaseController.cs

@@ -122,9 +122,8 @@ namespace Radarr.Api.V3.Indexers
             catch (Exception ex)
             {
                 _logger.Error(ex, "Movie search failed: " + ex.Message);
+                throw new NzbDroneClientException(HttpStatusCode.InternalServerError, ex.Message);
             }
-
-            return new List<ReleaseResource>();
         }
 
         private List<ReleaseResource> GetRss()