Merge pull request #11623 from Mailaender/zip-entry-null

Fixed a potential NRE in DownloadPackageLogic.ShowDownloadDialog

OpenRA.Mods.Common/Widgets/Logic/Installation/DownloadPackageLogic.cs

@@ -142,7 +142,7 @@ namespace OpenRA.Mods.Common.Widgets.Logic
 						foreach (var kv in download.Extract)
 						{
 							var entry = z.GetEntry(kv.Value);
-							if (!entry.IsFile)
+							if (entry == null || !entry.IsFile)
 								continue;
 
 							onExtractProgress("Extracting " + entry.Name);