PES-2964: fix refund order (#874)

Author: zemekoule

changelog.txt

@@ -1,4 +1,7 @@
 == Changelog ==
+= 2.1.2 =
+Fixed: Plugin no longer crashes on the orders list when a refunded order is present.
+
 = 2.1.1 =
 Fixed: Removing all transients and options upon uninstall.
 Updated: Checkout data transient lifetime raised to the default value of WooCommerce.