patch 8.2.1559: s390x tests work again

Problem:    s390x tests work again.
Solution:   re-enable s390x tests. (James McCoy, closes #6829)
diff --git a/src/version.c b/src/version.c
index 411a889..158f2a3 100644
--- a/src/version.c
+++ b/src/version.c
@@ -755,6 +755,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1559,
+/**/
     1558,
 /**/
     1557,