Update the @bug tag to the correct value:

$ hg diff
diff -r fba8635290df test/jdk/jdk/nio/zipfs/CopyMoveTests.java
--- a/test/jdk/jdk/nio/zipfs/CopyMoveTests.java Wed Oct 30 15:54:41 2019 -0400
+++ b/test/jdk/jdk/nio/zipfs/CopyMoveTests.java Tue Nov 05 13:20:28 2019 -0500
@@ -41,7 +41,7 @@
 
 /**
  * @test
- * @bug 8223771
+ * @bug 8231766
  * @summary Test Files::copy and Files::move with Zip FS
  * @modules jdk.zipfs
  * @run testng/othervm CopyMoveTests
ljanders-mac:open ljanders