Fix error with null dates

src/NzbDrone.Core/MetadataSource/SkyHook/SkyHookProxy.cs

@@ -142,7 +142,6 @@ namespace NzbDrone.Core.MetadataSource.SkyHook
             if (resource.release_date.IsNotNullOrWhiteSpace())
             {
                 movie.InCinemas = DateTime.Parse(resource.release_date);
-            }
 
                 // get the lowest year in all release date
                 var lowestYear = new List<int>();
@@ -154,6 +153,7 @@ namespace NzbDrone.Core.MetadataSource.SkyHook
                     }
                 }
                 movie.Year = lowestYear.Min();
+            }
 
             movie.TitleSlug += "-" + movie.TmdbId.ToString();