Fix CA1849

.editorconfig

@@ -762,6 +762,9 @@ dotnet_diagnostic.CA1846.severity = warning
 # Use string.Contains(char) instead of string.Contains(string) with single characters.
 dotnet_diagnostic.CA1847.severity = warning
 
+# Call async methods when in an async method.
+dotnet_diagnostic.CA1849.severity = warning
+
 # Unnecessary call to 'Dictionary.ContainsKey(key)'.
 dotnet_diagnostic.CA1853.severity = warning
 

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

@@ -239,7 +239,7 @@ namespace OpenRA.Mods.Common.Widgets.Logic
 
 										using (var zz = package.GetStream(kv.Value))
 										using (var f = File.Create(targetPath))
-											zz.CopyTo(f);
+											await zz.CopyToAsync(f);
 									}
 
 									package.Dispose();