added closing error window on esc

VeloeMinecraftLauncher/Views/ErrorWindow.axaml

@@ -78,6 +78,7 @@
 					</Button>
 					<Button
 						Content="Ok"
+						IsCancel="True"
 						Width="40"
 						Margin="10 0 0 0"
 						Command="{Binding CloseWindow}"