This has to be `escape`, too. It otherwise crashes the game:

```
Exception of type `System.InvalidOperationException`: FieldLoader: Cannot parse `esc` into `Key.OpenRA.Hotkey` 
  at OpenRA.FileFormats.FieldLoader.<InvalidValueAction>m__3 (System.String s, System.Type t, System.String f) [0x0001d] in /home/matthias/Projekte/OpenRA/OpenRA.FileFormats/FieldLoader.cs:25 
  at OpenRA.FileFormats.FieldLoader.GetValue (System.String fieldName, System.Type fieldType, System.String value, System.Reflection.MemberInfo field) [0x003d4] in /home/matthias/Projekte/OpenRA/OpenRA.FileFormats/FieldLoader.cs:191 
  at OpenRA.FileFormats.FieldLoader.LoadField (System.Object self, System.String key, System.String value) [0x00078] in /home/matthias/Projekte/OpenRA/OpenRA.FileFormats/FieldLoader.cs:93 
  at OpenRA.WidgetLoader.LoadWidget (OpenRA.Widgets.WidgetArgs args, OpenRA.Widgets.Widget parent, OpenRA.FileFormats.MiniYamlNode node) [0x0009a] in /home/matthias/Projekte/OpenRA/OpenRA.Game/Widgets/WidgetLoader.cs:56 
  at OpenRA.WidgetLoader.LoadWidget (OpenRA.Widgets.WidgetArgs args, OpenRA.Widgets.Widget parent, OpenRA.FileFormats.MiniYamlNode node) [0x00120] in /home/matthias/Projekte/OpenRA/OpenRA.Game/Widgets/WidgetLoader.cs:63 
  at OpenRA.WidgetLoader.LoadWidget (OpenRA.Widgets.WidgetArgs args, OpenRA.Widgets.Widget parent, System.String w) [0x00032] in /home/matthias/Projekte/OpenRA/OpenRA.Game/Widgets/WidgetLoader.cs:41 
  at OpenRA.Widgets.Ui.OpenWindow (System.String id, OpenRA.Widgets.WidgetArgs args) [0x00012] in /home/matthias/Projekte/OpenRA/OpenRA.Game/Widgets/Widget.cs:47 
  at OpenRA.Game.OpenWindow (System.String widget, OpenRA.Widgets.WidgetArgs args) [0x0003f] in /home/matthias/Projekte/OpenRA/OpenRA.Game/Game.cs:94 
  at OpenRA.Mods.RA.Widgets.Logic.MainMenuLogic.OpenSkirmishLobbyPanel () [0x00053] in /home/matthias/Projekte/OpenRA/OpenRA.Mods.RA/Widgets/Logic/MainMenuLogic.cs:122 
  at OpenRA.Mods.RA.Widgets.Logic.ConnectionLogic.ConnectionStateChanged (OpenRA.Network.OrderManager om) [0x0001f] in /home/matthias/Projekte/OpenRA/OpenRA.Mods.RA/Widgets/Logic/ConnectionLogic.cs:27 
  at (wrapper delegate-invoke) System.Action`1<OpenRA.Network.OrderManager>:invoke_void__this___T (OpenRA.Network.OrderManager)
  at OpenRA.Game.Tick (OpenRA.Network.OrderManager orderManager) [0x0002d] in /home/matthias/Projekte/OpenRA/OpenRA.Game/Game.cs:123 
  at OpenRA.Game.Run () [0x0007b] in /home/matthias/Projekte/OpenRA/OpenRA.Game/Game.cs:463 
  at OpenRA.Program.Run (System.String[] args) [0x00011] in /home/matthias/Projekte/OpenRA/OpenRA.Game/Support/Program.cs:114 
  at OpenRA.Program.Main (System.String[] args) [0x0005a] in /home/matthias/Projekte/OpenRA/OpenRA.Game/Support/Program.cs:38
```