fix hotkey entry

Author: patrickwieth

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

@@ -71,7 +71,7 @@ public ModContentPromptLogic(ModData modData, Widget widget, ModContent content,
 				Ui.CloseWindow();
 				continueLoading();
 			};
-			continueButton.HotKey = Hotkey.FromConfigString("escape");
+			continueButton.Key = modData.Hotkeys["escape"];
 			continueButton.GetText = () => continueMessage;
 
 			Game.RunAfterTick(Ui.ResetTooltips);