patch 8.2.1986: expression test is flaky on Appveyor

Problem:    Expression test is flaky on Appveyor.
Solution:   Temporarily disable the test in MS-Windows.
diff --git a/src/version.c b/src/version.c
index 8174386..b78e0b5 100644
--- a/src/version.c
+++ b/src/version.c
@@ -751,6 +751,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1986,
+/**/
     1985,
 /**/
     1984,